Does James’ theology differ from Paul’s theology?
Some people would have you believe that James and Paul contradict each other on faith-only salvation verses works being required.
Romans 9:30-32 NIV– Paul
What then shall we say? That the Gentiles, who did not pursue righteousness, have obtained it, a righteousness that is by faith;  but the people of Israel, who pursued the law as the way of righteousness, have not attained their goal.  Why not? Because they pursued it not by faith but as if it were by works. They stumbled over the stumbling stone.
James 2:18-22 NKJV– James
But someone will say, “You have faith, and I have works.” Show me your faith without your works, and I will show you my faith by my works.  You believe that there is one God. You do well. Even the demons believe-and tremble!  But do you want to know, O foolish man, that faith without works is dead?  Was not Abraham our father justified by works when he offered Isaac his son on the altar?  Do you see that faith was working together with his works, and by works faith was made perfect?
Paul never attacked the Judaic Jews because of works. He attacked their works because they felt that works would save them.
James shows his audience that works without faith would not save, neither would “claimed faith” without works save.
Why wouldn’t faith alone save? That’s not what James is saying. James is saying that while faith alone does save, your faith is completed by obedience to God and His laws. Without obedience to God, your intellectual faith is dead. Simply put, you don’t have enough faith to produce action for your faith.
Take baptism. Jesus commanded for believers to be baptized in His name. To refuse baptism in His name is to refuse to obey Him. Thus, no matter how much faith you say you may have, you have refused to obey Jesus and have shown you do not have enough faith to obey Him, making your faith dead.
If James really did differ from Paul’s view, then James should’ve written against Paul. Instead, James refused to do so, counting Paul as another brother in Christ.