My brethren, count it all joy when you fall into various trials, knowing that the testing of your faith produces patience. But let patience have its perfect work, that you may be perfect and complete, lacking nothing. (Jam 1:2-4 NKJ)
Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ, through whom also we have access by faith into this grace in which we stand, and rejoice in hope of the glory of God. And not only that, but we also glory in tribulations, knowing that tribulation produces perseverance; and perseverance, character; and character, hope. (Rom 5:1-4 NKJ)
Why are trials useful? Paul expands on James’ exhortation to, “count it all joy when you fall into various trials.” First, Paul tells us that trials produce endurance. (v. 3) In effect, trials are exercises for developing spiritual muscle and strength. This is true for relationships in church life and personal spiritual growth. The Bible often uses the analogy that life is a race, and as Hebrews 12 tells us, endurance helps us “complete the race set before us.” So rejoice, trials are part of God’s training regime for you.