Just like a good tree will bear good fruit and a bad tree will only produce poor fruit (Matthew 7:16-17)…our walk with the Lord is all about fruit production. You may have a hundred Bible verses memorized, but if you never put them into usable application…what good are they? Here James is saying, I will show you my faith by taking what I learned and witnessed about the Lord Jesus Christ and put it into practical action. In other words, a work-less faith is a worthless faith when at the end of the day there is no fruit (good works) to show for it.
So what exactly were the apostles doing that would land them in jail? It tells us that they were performing many miraculous signs and wonders…healing the sick and tormented…and that many were coming to believe in the Lord Jesus Christ. They were doing good stuff, but they were also persecuted for it. Contention within the Body can degenerate into negative emotions that desire to make war against the good they see others doing…simply because it’s not them performing it. They feel threatened, so they attempt to discount and belittle rather than praising God for what He’s doing. Doing good regardless…it tells us in I Peter 3:17 that we may have to suffer in doing good…and that we shouldn’t become weary in doing it. (Galatians 6:9) I pray we all may have the boldness to continue doing good no matter the cost.