According to Paul, a person is justified by faith alone apart from works, that is, prior to doing any work, a person is justified simply by believing in Jesus.
Paul made this clear in his statements in Rom 4:2-6
"if Abraham was justified by works, he has something to boast about, but not before God. For what does the Scripture say? "Abraham believed God, and it was accounted to him for righteousness." (Gen 15:6) Now to him who works, the wages are not counted as grace but as debt. But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness, just as David also describes the blessedness of the man to whom God imputes righteousness apart from works"
In contrast James view a man as not being justified by faith alone, but is only justified when he adds works to his faith. That is to him salvation is contingent upon faith+works.
He makes this clear in the second half of the second chapter of his letter. "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? And the Scripture was fulfilled which says, "Abraham believed God, and it was accounted to him for righteousness." (Gen 15:6) And he was called the friend of God. You see then that a man is justified by works, and not by faith only."
Both Paul and James mention Gen 15:6, so both are referring to the same concept of being accounted righteous, what we call "justification". While Paul's argument is contingent upon interpreting Gen 15:6 as being fulfilled right then in Gen 15:6, prior to Abraham's work, James' argument is contingent upon viewing Gen 15:6 as a prediction which was not fulfilled until Gen 22 when Abraham attempted to sacrifice Isaac (a work), prior to which according to James, his faith was "dead".
While Protestants attempt to resolve this contradiction by misreading James, and Catholics attempt to resolve this contradiction by misreading Paul, in fact Paul and James have incompatible views concerning requirements for justification.
Paul, an apostle chosen personally by Jesus Christ, and even agreed upon by James along with the other apostles in Acts 15 as being the apostle to the Gentiles, trumps James, who is not an apostle of Jesus Christ.
Are there any other opinions concerning Paul and James' interpretation of Gen 15:6?