The suppose contradictions of the Bible never go away. No matter how many times you prove that there is not contradiction it continues to be use to deceive the unstudied and unstable. The difference in Paul's preaching and James' is just one example. Is it by faith or faith and works? Or does the Bible contradict itself?
2 Peter 3:16 As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction.
This supposed contradiction is a staple of those that want to bring us back under bondage to the law teaching works for salvation. Was Abraham justified by faith or by works?
Romans 4:2-5 For if Abraham were justified by works, he hath whereof to glory; but not before God. 3For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. 4Now to him that worketh is the reward not reckoned of grace, but of debt. 5But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.
James 2:21 Was not Abraham our father justified by works, when he had offered Isaac his son upon the altar?
Do these two passages contradict? They probably would if they were speaking of the same thing. Paul is speaking of our eternal salvation, James is speaking of one incident in Abraham's life: "when he had offered Isaac his son upon the altar." James is speaking of an incident where God tested, tried, Abraham's faith.
Hebrews 11:17 By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son,
1 Peter 1:7 That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ:
Abraham was saved by his faith alone, but God tested that faith and by his works Abraham proved, perfected, his faith.
James 2:22-23 Seest thou how faith wrought with his works, and by works was faith made perfect? 23And the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness:
Salvation is by grace through faith and not of works. There are no contradictions in the Bible; there are those that have not studied it diligently with a right heart toward God.
When it comes to our eternal salvation, it is by grace, not works. Grace and works are mutually exclusive, one cannot exist with the other. If I give you a free gift and there is a payment book attached, it is not a gift and it is not free. Salvation is the free gift of God.
Romans 11:6 And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.
To teach that works have any part in our eternal salvation is to pervert the gosple of Jesus Christ. Works play apart in this life but not in obtaining the life to come.