James was the brother of Jesus.  But notice James does not list that fact. He calls himself a “servant” of Jesus. Josephus says that James was the bishop of the church in Jerusalem. This would be the followers of the Way, made up mostly of the Messianic Jews there.

James 1:1-6
James, a servant of God and of the Lord Jesus Christ, To the twelve tribes scattered among the nations:
While James' letter is for all of us today, the writing of the letter is addressed specifically to the scattered tribes as far as Western Europe.

Greetings. Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance. Perseverance must finish its work so that you may be mature and complete, not lacking anything.
Quite a tall order to consider all these trials and testings pure joy! Testing that comes our way is not for God to see what we will do. It’s for us to see what God will do through the testing. Can we have faith that is mature and complete without the trials, testing, and perseverance?

If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him. But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind.
God gives wisdom generously to those who ask, if they believe and not doubt.

James 1:22
Do not merely listen to the word, and so deceive yourselves. Do what it says.
It's very easy to listen to a pastor on Sunday morning and be lulled into an assumption that we don't need to do anything more than that. We are deceived if we think that.

James 2:19
You believe that there is one God. Good! Even the demons believe that-- and shudder.

James makes it very clear in the previous two verses that merely listening to the Word or just believing is not enough. Those who just believe are “shadow makers” in the pews. The idea is not to just believe there is a God but instead believe in the God that is just. We must believe in Him, not just acknowledge he exists, even the demons do that.

James 3:2a
We all stumble in many ways.
And yet our ever faithful God catches us as we stumble and sets us back on the right track.

James 4:1-4
What causes fights and quarrels among you? Don't they come from your desires that battle within you? You want something but don't get it. You kill and covet, but you cannot have what you want. You quarrel and fight. You do not have, because you do not ask God.

This scripture is often taken out of context. Look what comes after that.

When you ask, you do not receive, because you ask with wrong motives, that you may spend what you get on your pleasures. You adulterous people, don't you know that friendship with the world is hatred toward God? Anyone who chooses to be a friend of the world becomes an enemy of God.
Ouch!Jude was most likely writing to Jewish believers and not to the Gentile churches. Gentile believers didn’t have the background of Hebrew and Jewish teaching to fall back on. Probably most of the Gentiles had had some deity they worshiped before being introduced to Messiah Jesus. This naturally polluted their ways of worship once they became “the church”. And they, no doubt were letting some of their pagan practices creep into their church. Jude was warning the Jewish believers, followers of The Way, of this. Are we any different in the church today mixing myths, fantasies, and pagan practices?

So Jude lays out a warning about false teaching and apostasy. But we all know that this apostasy or a falling away from the truth begins with apathetic people. Apathetic people are uninterested, unconcerned, lethargic, and basically lazy. Jude is saying to us that many will be led astray by this false teaching, especially if they are apathetic. However, we as believers in Jesus should not be led astray. We should be just the opposite of apathetic. We should be interested, concerned, enthusiastic, and energetic. While we will read about many warnings from Jude, we need to remember that we who are believers in Jesus as Messiah are different from the world. We need to act like we are!