ps: 2:14 isn't the 'context' of the chapter. The question is in regards to being saved from "what", exactly. Is it the lake of fire? Why would anything think that in this book?
In fact, James gives us a very clear understanding of what he meant in the very next 2 verses:
15 If a brother or sister is without clothing and in need of daily food, 16 and one of you says to them, Go in peace, be warmed and be filled, and yet you do not give them what is necessary for their body, what use is that?
What's his point here? What do we call those who act like this? Hypocrites is what. Jesus used that word on the Pharisees many times. James is warning believers that they need to demonstrate their faith or they'll be charged with hypocrisy.
James even makes the point more clear in v.18 -
18But someone may well say, You have faith and I have works; show me your faith without the works, and I will show you my faith by my works.
iow, if one doesn't show their faith by works, others will not see it. This complements v.15-16 very well. If believers aren't meeting the needs of others, they aren't demonstrating their faith. So when they say they are Christians, but aren't demonstrating it, they are being hypocrites.
Given how often Jesus chided the legalistic Pharisees for being hypocrites, I have no doubt that left quite an impression on His half brother James, who grew up with Jesus.
But I'm aware of the RCC view that Mary was a perpetual virgin. But that doesn't affect the truth of Scripture. Jesus had brothers and sisters because the Bible says so.