I believe that the way to reconcile James with the rest of the Bible, Paul, is to realize that a) James and other saints were Judaizers to extents, influencing the churches and Paul:
If there comes into your synagogue a man with gold rings in splendid clothing...
Paul went in with us to James, and all the elders were present.
And having greeted them, he related one by one the things which God did among the Gentiles through his ministry. And when they heard it, they glorified God and said to him, You observe, brother, how many thousands there are among the Jews who have believed; and all are zealous for the law. And they have been informed concerning you that you are teaching all the Jews throughout the nations apostasy from Moses, telling them not to circumcise their children, nor to walk according to the customs.
What then is to be done? They will certainly hear that you have come. Therefore do this that we tell you: We have four men who have a vow on themselves; take these and be purified with them, and pay their expenses that they may shave their heads. And all will know that there is nothing to the things that they have been informed of concerning you, but that you yourself also walk orderly, keeping the law. But concerning the Gentiles who have believed, we have already written, having decided that they should keep themselves from idol sacrifices and blood and anything strangled and fornication.
Before some came from James, [Cephas] continually ate with the Gentiles; but when they came, he began to shrink back and separate himself, fearing those of the circumcision.
13 And the rest of the Jews also joined him in this hypocrisy, so that even Barnabas was carried away in their hypocrisy. But when I saw that they were not walking in a straightforward way in relation to the truth of the gospel, I said to Cephas before them all, If you, being a Jew, live like the Gentiles and not like the Jews, how is it that you compel the Gentiles to live like the Jews? We are Jews by nature and not sinners from among the Gentiles; and knowing that a man is not justified out of works of law, but through faith in Jesus Christ, we also have believed into Christ Jesus that we might be justified out of faith in Christ and not out of the works of law, because out of the works of law no flesh will be justified.
Certain men came down from Judea and began to teach the brothers, Unless you are circumcised according to the custom of Moses, you cannot be saved. And when no little dissension and discussion with them came about through Paul and Barnabas, the brothers directed Paul and Barnabas and certain others among them to go up to the apostles and elders in Jerusalem concerning this question...And when they finished speaking, James answered, saying, Men, brothers, listen to me...I judge that we write to [those from the Gentiles who are turning to God] to abstain from the contaminations of idols and...what is strangled and blood. For Moses from ancient generations has in every city those who proclaim him in the synagogues, he being read every Sabbath.
Jam 2; Ac 21; Gal 2; Ac 15.
And that b), kinda in line with user33515's comment above---How do you define "salvation"?---, Paul, in Gal 2:16 and Rm 3:21-28, addresses nonbelievers, 'sinners,' becoming believers. James's letter, re faith, justification, works, and salvation, addresses us believers' judgment by God (resulting in reward or loss--punishment. Not to our eternal destiny. Paul also, elsewhere, addresses judgment of believers.) There are these 2 broad judgments (Mt 24:45--25:30; Rv 20:11-15. And even a third, particular one, Mt 25:31-46).
Speak and so do as those who are to be judged by the law of freedom. For the judgment is without mercy to him who has shown no mercy; mercy triumphs over judgment. What is the profit, my brothers, if anyone says he has faith but does not have works? Can that faith save him?