This verse is sometimes misunderstood because of its use of the word perfect. The Greek word used here does not mean sinless. It means mature or full-grown. James is saying that enduring trials and finding joy in them will help a babe in Christ reach spiritual maturity. We don't go through trials in order to come out sinless but to become mature, fit for God's purposes. If you use afflictions, ridicule, pain, suffering, adversity, or any other trial for the purpose of spiritual development, then you will become more like the person God wants you to be! In the end, you won't lack anything, spiritually speaking; you'll be complete and mature in Christ.
But, sadly, too many Christians have a weak faith. They don't survive the trials of life. They sin in the midst of trials by quitting and becoming unfaithful to the Lord. They blame God and fail to persevere when things happen that they can't understand. James addressed this point further in the next verse.
"If any of you lacks wisdom, let him ask of God, who gives to all liberally and without reproach, and it will be given to him" (1:5). No one said it would be easy to rejoice and see the blessings in trials; it takes wisdom to do this. And James plainly tells us that God will provide the necessary wisdom if we ask for it and seek it. True wisdom is knowing and doing what is right and best in the choices life gives us. The only source of such wisdom is God.
Now, don't make the mistake of assuming that we receive this wisdom in some direct and mysterious way simply by asking. I don't believe that's what James meant. After all, we are taught to ask for our daily bread also (Matt. 6:11), but the man who thinks it will miraculously appear on his table, sliced and ready to eat, is going to be disappointed! Though we must ask, and though we recognize it as a gift of God, we must labor for our daily bread. We cannot neglect the means that God has given us for supplying our daily bread. Likewise we cannot neglect the means that God has provided to supply us with wisdom: the careful study and application of His word!
James continued in 1:6,7 by stating - "But let him ask in faith, with no doubting, for he who doubts is like a wave of the sea driven and tossed by the wind. For let not that man suppose that he will receive anything from the Lord." These verses remind me of Hebrews 11:6 ("without faith it is impossible to please Him"). When we ask God for wisdom, daily bread, or anything else, we have to have the confidence that we will receive it; that is, we must ask in faith. We can't be hesitant or wavering for such is displeasing to the Lord, and consequently we shouldn't expect to receive that for which we ask when we ask with doubt.
Now, let me challenge your thinking on this point. True, living faith, in addition to a confident expectation, also includes the idea of obedience! James 2:26 declares "faith without works is dead." So, putting these two passages together, we can see that when we ask in faith we must also act accordingly, otherwise our faith is dead and useless. Thus, when we ask for wisdom, we must also be actively seeking it. When we pray for church growth, we must actively work toward it. Other examples could be given, but the point should be clear.
Finally, 1:8 reads - "He is a double-minded man, unstable in all his ways." This sentence merely describes the kind of individual who asks God for something but doesn't really believe it will come to pass. His actions are hypocritical; he is double-minded. Such displeases the Lord.
May we all seek spiritual maturity and wisdom from the Lord, His book, and the trials by which our faith is tested. May we always endeavor to ask God in faith with no doubting.