James, a bond-servant of God and of the Lord Jesus Christ, To the twelve tribes who are dispersed abroad: Greetings.  Consider it all joy, my brethren, when you encounter various trials,  knowing that the testing of your faith produces endurance.  And let endurance have its perfect result, so that you may be perfect and complete, lacking in nothing.
The final principle James teaches us about responding to trials is in verse 4. James says “And let endurance have its perfect result.” In other words, we must allow our trials to fulfill their intended purpose. Two quotes from men I highly respect shed light on this principle.
Pastor and author Derek Prime says, “One of the dangers of trials, either when they actually happen or as we see them appear on the horizon of our life, is our tendency to try to escape them in some way or another, or to endeavor to avoid their full force rather than to see them through to God's planned conclusion. We must deliberately let endurance show itself in practice. We must prove to ourselves – as well as to the silent spectators who may be watching to see how real our faith is when it is tested – that perseverance is both possible and profitable.
Isobel Kuhn, in her book, Green Leaf in Drought Time, describes how some missionary friends found great encouragement in Andrew Murray's formula for trial.
1. Say, He brought me here. It is by His will I am in this strait place and in that fact I will rest.
2. He will keep me here in His love and give me grace to behave as His child.
3. Then He will make the trial a blessing, teaching me the lessons He intends for me to learn.
4. In His good time He can bring me out again – how and when He knows. So let me say, I am (1) here by God's appointment; (2) in His keeping; (3) under His training; (4) for His time.”
The great 20th century expositor Ray Stedman said this about trials. “Undoubtedly, one of the greatest misconceptions held by many is that being a Christian means that life should suddenly smooth out, mysterious bridges will appear over all chasms, the winds of fate will be tempered, and all difficulties will disappear. No, Christianity is not membership in some red-carpet club. All the problems and pressures of life remain, or are even intensified. Christians must face life in the raw, just as any pagan will. The purpose of the Christian life is not to escape dangers and difficulties but to demonstrate a different way of handling them. There must be trouble, or there can be no demonstration.”
In short, if our trials are going to fulfill their intended purpose we must cooperate! The writer of Hebrews makes this same point in 12:5-11. “And you have forgotten the exhortation which is addressed to you as sons, "My son, do not regard lightly the discipline of the Lord, Nor faint when you are reproved by Him;  For those whom the Lord loves He disciplines, And He scourges every son whom He receives."  It is for discipline that you endure; God deals with you as with sons; for what son is there whom his father does not discipline?  But if you are without discipline, of which all have become partakers, then you are illegitimate children and not sons.  Furthermore, we had earthly fathers to discipline us, and we respected them; shall we not much rather be subject to the Father of spirits, and live?  For they disciplined us for a short time as seemed best to them, but He disciplines us for our good, so that we may share His holiness.  All discipline for the moment seems not to be joyful, but sorrowful; yet to those who have been trained by it, afterwards it yields the peaceful fruit of righteousness.
James calls persecution trials. The writer of Hebrews calls persecution the Lord’s discipline. So you see, trials and discipline are one and the same. In Hebrews 12:11 it says the result of discipline is the peaceful fruit of righteousness. The fruit of righteousness is equal to the mature Christian character James refers to. What’s my point? Our Heavenly Father designs trials for our lives because he loves us and seeks our good! He wants us to share in His holiness! Can there be any better reason to cooperate with Him and allow our trials to fulfill their intended purpose?