This chart gives a timeline of the major events in the life of the Apostle Paul and the dating of his letters.
James and Paul appear to contradict each other because they use the same vocabulary: faith, works and justification. Plus they both appeal to Abraham. But they use the same language in very different contexts to address different problems and answer different questions.
Paul claims you can have utter confidence in the gospel message he preaches because he received it by revelation from Jesus Christ, not human invention.