LET GOD PRUNE YOU HIS WAY
John 15:2 "Every branch in me that beareth not fruit he taketh away: and every branch that beareth fruit, he purgeth it, that it may bring forth more fruit."
This purging has been interpreted in many ways. The illustration that Jesus is using is one of pruning; therefore, some have said this purging is a very painful process where the Lord cuts and slashes us through things like sickness, death, poverty, and other forms of tragedy so that eventually we will bear more fruit. This teaching not only promotes problems as being good, but necessary, if we want to bear more fruit.
That thinking is not consistent with the rest of God's Word or even the context of this verse. The text makes it very clear that the purging that Jesus speaks of is done through the Word that He has spoken unto us.
Paul said in 2 Timothy 3:16-17 that God's Word was given to us "for doctrine, for reproof, for correction, and for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works." That is God's method of pruning us, and He doesn't need the devil's help. His word will make us "perfect, thoroughly furnished unto all good works."
That is not to say that we cannot learn through tragedy: but God has a better way. If we mistakenly think that God is bringing tragedy into our lives to make us more fruitful, then we'll not resist the tragedies and they will not flee from us. All of us will learn by hard knocks, but the man who welcomes them with wide open arms will suffer greatly and be far behind the man who lets God's Word have His perfect work in him.