Did Jesus have a sin nature?

    No, Jesus did not have a sin nature.  However, that has not stopped the Christadelphians from teaching He did.  This is not surprising considering they deny the doctrine of the Trinity and the deity of Jesus.  As with all non-Christian cults that deny the true doctrine of God, other doctrines necessarily become incorrect as well. In this case, their error is that Jesus has a sin nature.

• "Therefore, we conclude that it is not only that Jesus was called a sinner at his trial by his enemies or that he was 'numbered with the transgressors' when he was crucified between two thieves, but more particularly that he shared the very nature which had made a sinner out of ever other man who had borne it.  It is for this reason that the nature we bear is called "sinful flesh" or more briefly, 'sin' (Rom. 7:20 and 8:4)." (The Christadelphians: What They Believe and Preach, p. 74)
• "And it was for that very reason -- being a member of a sinful race -- that the Lord Jesus himself needed salvation...But it is equally true that, being 'made sin for us' (2 Cor. 5:21), he himself required a sin offering; in other words, he sacrificed himself, for himself, that he might save us.  Or, in other words, he saved himself in order to save us...That Christ needed salvation is seen from Psalm xci.16." (Christadelphian Answers, p. 24)

     One of the main verses they use to support their erroneous doctrine is Rom. 8:3-4 which says, "For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh."  They teach that the "likeness of sinful flesh" means that Jesus had a sinful nature.  But it doesn't.  The key to understanding this verse is the word "likeness." If this word were omitted then the text would say "...sending His own Son in sinful flesh..."  If that is what the verse said then the Christadelphians would have a valid argument. But the text says that Jesus came in the "likeness" of sinful flesh, not that He came in sinful flesh.  In other words, men are sinners.  Jesus appeared as a man. Therefore, Jesus appeared in the likeness of a sinner, though He was not a sinner.  
     Another verse they use is Heb. 2:14 which says, "Since then the children share in flesh and blood, He Himself likewise also partook of the same, that through death He might render powerless him who had the power of death, that is, the devil."  This verse can easily be explained in the same manner as Rom. 8:3-4 above.  Jesus partook of flesh and blood.  But it does not here say that He had a sin nature.
     To have a sin nature means that Jesus had a fallen, defiled, and unholy nature. I fail to see how an unholy person can offer a holy sacrifice sufficient to please an infinitely holy God.  Of course, the Christadelphians say this is possible because, even though Jesus had a sin nature, He never committed a sin and He kept the Law therefore satisfying God.  But that still doesn't answer the objection:  If Jesus had a sinful and unholy nature, how is it possible for Him to provide a sinless and holy sacrifice especially since Eph. 2:3 states that we are by nature children of wrath?  This means that the natural state of the fallen is judgment.
     The problem with the Christadelphian position is that the Bible teaches us the sacrifice to God must be without blemish. Deut. 17:1 says, "You shall not sacrifice to the Lord your God an ox or a sheep which has a blemish or any defect, for that is a detestable thing to the Lord your God." (See also Ezekiel 43:22-23, 25; 45:18, 23 for the same theme.). Of course, Jesus is not an animal, but it is clear that the pattern for the sacrifice was that it have no defect at all.  Why?  Because God is holy and God doesn't accept imperfect sacrifices!  To have a sinful nature is definitely to have a defect.  Contrary to Christadelphian teaching, we can see from the Bible that Jesus has no defect, no blemish: "How much more will the blood of Christ, who through the eternal Spirit offered Himself without blemish to God, cleanse your conscience from dead works to serve the living God?" (Heb. 9:14).  This verse states that Jesus is without blemish.  How can He be without blemish if He has a fallen and sinful nature?  
     For the Christadelphians to maintain that Jesus had a sinful nature is the same as saying that the offering He made had a defect.  We can see that this is a problem because the High Priests of the Old Testament were fallen and had, themselves to be cleansed in order to offer the sacrifice to God.  It wasn't simply that they were sinners.  They were fallen by nature and were unholy. 
     Because the Christadelphians teach that Jesus had a fallen and sinful nature, there faith is in a defiled and imperfect sacrifice.  It is, therefore, is insufficient.  They are lost.

What does it mean to have a sin nature?

     When we speak of the nature of something, we speak of its essence, character, and quality.  The essence of God, for example, is holiness, purity, sinlessness, etc. The essence of people, on the other hand, is sinful.  In Mark 7:21-23, Jesus discloses to us the very nature of our hearts when He said, "“For from within, out of the heart of men, proceed the evil thoughts, fornications, thefts, murders, adulteries, ²²deeds of coveting and wickedness, as well as deceit, sensuality, envy, slander, pride and foolishness. ²³“All these evil things proceed from within and defile the man,” (NASB).  This is why it says in Eph. 2:3 that we are by nature children of the wrath; our hearts are sinful by nature which is the source of the sins listed by Jesus.  This is also why Paul said in Rom. 7:18 that nothing good dwelt in him, that is, in his flesh.  Paul knew his nature was sinful and because it was He was lost and without hope (except for his faith in Jesus and His unblemished sacrifice).  
     Are we to conclude from Christadelphian thinking that Jesus' fallen, unholy, and sinful nature produced a pure and perfect sacrifice without defect?  How is that possible?  How is it possible for someone unholy to offer a holy sacrifice?  How is it possible for someone that is sinful by nature, to offer a sinless sacrifice?  Just because Jesus never sinned doesn't mean that He was perfect.  If He had a sin nature, He was not perfect.  He was flawed.  His sacrifice would be useless. 
    However, to the Christadelphians, the issue is not so much Jesus' sinful and fallen nature, as it is His ability to keep the Law.  Therefore, in Christadelphianism we have a man, Jesus, with a sinful nature being able to perfectly keep all of God's law. Contrast this with Adam who was made sinless and yet to was not able to keep the law of God.  How can Jesus have a sinful and unholy nature and yet be sinless and holy as a perfect, unblemished sacrifice?  He cannot.  The Christadelphians are wrong.

Jesus was tempted

     One of the reasons the Christadelphians believe Jesus had a sinful nature is their claim that in order for Jesus to be tempted, He had to have a sin nature.  But, this does not logically follow.  Adam did not have a sinful nature and he was tempted successfully.  He fell.  Jesus did not have a sinful nature.  He was tempted unsuccessfully.  He did not fall.  So, Jesus not having a sin nature does not mean He cannot be tempted.
     Of course, the Christadelphians deny that Jesus is both God and man, even though this is what Col. 2:9 says:  "For in Him all the fullness of Deity dwells in bodily form."²  In their quest to support their view, they sometimes quote James 1:13 which states that God cannot be tempted by evil.  They ask, if Jesus is God, then how could He be tempted with evil?  This is a fair question and, to be honest, a bit difficult to answer because the Scriptures do not explicitly explain it.  Therefore, we have to work from what we do know using reason.
     If Jesus' human nature existed by itself, apart from the divine nature, it would have been a normal human nature and capable of sin.  But, Jesus' human nature is not separate from His divine nature which is morally pure and incapable of sin.  It would then seem that Jesus was able to be tempted in His human nature but not in His divine.  In the one person of Christ, there dwells two natures:  God and man (Col. 2:9).  As God, Jesus could stand without the danger of sinning.  As man, He could be tempted.  Exactly how these two natures relate to each other in one person is not clarified in scripture.  But, as you can see, it is possible that Jesus be divine and be tempted at the same time because He was both God and man.  To say that Jesus had to have a sin nature in order to be tempted is incorrect.  Rather, in order to be tempted, Jesus had to be human.

Jesus was under the Law

    Another Christadelphian argument that Jesus had a sin nature is that since Jesus was under the Law, and that a person is only under the Law if he is capable of sin, therefore Jesus had to have a sin nature.  As I've already demonstrated above, Adam did not have a sin nature and he was tempted.  But more importantly here, Adam was under the law of God even though he had a sinless nature -- though he was capable of sinning.  God gave a Law to Adam when He said, "...From any tree of the garden you may eat freely; ¹⁷but from the tree of the knowledge of good and evil you shall not eat, for in the day that you eat from it you shall surely die," (Gen. 2:16-17).  The phrase "you shall not" should remind us of the Ten Commandments with the "you shall" and "you shall not's."  Adam was under Law and because He broke that Law, he sinned.  Rom. 3:20 says, "...through the Law comes the knowledge of sin."  And, "sin is not imputed when there is no law," (Rom. 5:13).   
    The reason Jesus was under the Law was so that He could become a sacrifice for us and redeem those who are under the Law (Gal. 4:4).  He had to be made like His bretheren in order to satisfy the Law requirements of being a sacrifice.  He had to be a man to atone for men.  He had to be God in order to offer a sufficiently valuable atoning work.  

Sin entered the world through Adam

     There is debate in the theological circles concerning whether or not the sinful nature is passed down through the father or not. The scripture is not specific about this issue, so I present this argument as food for thought because it could shed some light on whether or not Jesus had a fallen nature.
     Even though Eve was the first person to sin, sin entered the world through Adam and not through Eve. Rom. 5:12 says, "Therefore, just as through one man sin entered into the world..."  The theory is that Adam was the representative of mankind in the garden.  When he fell, we fell because we were "in" him.  This concept of representation one person representing others is found in Heb. 7:9-10.

And, so to speak, through Abraham even Levi, who received tithes, paid tithes, ¹⁰for he was still in the loins of his father when Melchizedek met him.

     Levi was a distant descendant of Abraham. Abraham was long dead when Levi was born. But the text says that Levi paid tithes to Melchizedek. How is this possible? It seems the answer lies in the idea that one person represented his descendants. This would explain why Levi is said to have paid tithes to Melchizedek because his distant father Abraham did so and because Levi was "in" the loins of his distant father Abraham.  Likewise, sin entered the world through Adam and not Eve because Adam was the representative head of mankind.  If this is so, then Jesus would not have received a sin nature from His father Joseph since Joseph had no biological paternity in relation to Jesus. Therefore, his sin nature would not have been passed down to Jesus.  But since he had a human mother, He had human nature. We can see He was both God and man because He is called both the son of God and the son of man.  If it is true, then we can see that Jesus had a divine nature received from God and a human nature, but not a sinful one, from His mother Mary.  
     Whether or not the preceding concept is legitimate is still up for debate. But I offer it has yet another possible reason why Jesus did not have a sinful nature.

Jesus is God in flesh

     The primary biblical reason that in Jesus does not have a sinful nature is because Jesus is both God and man in one person. Of course the Christadelphians do not accepted this since they deny the Trinity.  Nevertheless, their denial of the deity of Christ does not negate its truth. The Bible says that Jesus is God in flesh.

• "but at the proper time manifested, even His word, in the proclamation with which I was entrusted according to the commandment of God our Savior," (Titus 1:3).
• For in Him all the fulness of Deity dwells in bodily form," (Col. 2:9).
• But of the Son He says, “Thy throne, O God, is forever and ever..." (Heb. 1:8).
• "looking for the blessed hope and the appearing of the glory of our great God and Savior, Christ Jesus," (Titus 2:13).

In the beginning was the Word, and the Word was with God, and the Word was God. ² He was in the beginning with God....¹⁴And the Word became flesh, and dwelt among us, and we beheld His glory, glory as of the only begotten from the Father, full of grace and truth," (John 1:1-2, 14).

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1.    All scripture quotes are from the NASB.
2.    Christadelphians compare Col. 2:9 with Eph. 3:19 which has similar phraseology in it in an effort to deny that Col. 2:9 says Jesus is deity.  For a more detailed look at this, see the paper "Col. 2:9 and Eph. 3:19."