Salvation by Faith or Works? (James vs Paul)

After some research I've found some information on who Jesus chosen to lead before he left the disciples, evidence of Paul's writings that he has different ideas about the laws with other Disciples including James brother of Jesus, Peter and Barnabas and in current Bible New Testament both opinions are different about Salvation (Faith and Works). Finally, I found Jesus prophecy and warnings in future for those that came to Jesus that they have used his name but did not follow his original teachings.

1. Who was Chosen by Jesus to Lead after he depart?

Jesus actually says in the Gospel of Thomas 12.
The disciples said to Jesus, "We know that you are going to leave us. Who will be our leader?"
Jesus said to them, "No matter where you are you are to go to James the Just, for whose sake heaven and earth came into being."

Answer: Jesus had chosen James as the Leader

2. Saint Paul Speaks About James and Other Disciple (Conflict of ideas about laws of circumcision)

Galatians 2:12-13 - For before certain men came from James, he used to eat with the Gentiles. But when they arrived, he began to draw back and separate himself from the Gentiles because he was afraid of those who belonged to the circumcision group. (12)
The other Jews joined him in his hypocrisy, so that by their hypocrisy even Barnabas was led astray. (13)

Summary: Paul disagree with other Disciples including James, Peter and Barnabas (He said Barnabas was led astray)

3. Dispute of Laws of Faith and Works in Current Bible

James 2:24 - You see that a man is justified by works and not by faith alone.

Galatians 2:16 - Nevertheless knowing that a man is not justified by the works of the Law but through faith in Christ Jesus, even we have believed in Christ Jesus, that we may be justified by faith in Christ, and not by the works of the Law; since by the works of the Law shall no flesh be justified.

Difference Summary:

James - A Man justified by works and not by faith alone.
Paul - A Man is not justified by works but through faith alone.

4. What did Jesus Prophecies (Warned us)?

Matthew 7:21-23

“Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of My Father in heaven. (21) Many will say to Me in that day, ‘Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?’ (22) And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness!’ (23)

Summary: Jesus prophesised many people will come to him in the end times, and told them that they prophesised and done wonders in Jesus name, but Jesus will declare to them 'I never knew you, depart from me, you who practice lawlessness!' What does lawlessness means? Those who does not follow the original teaching of Jesus and the prophets.