"You will have tribulation in this world." John 16:33
The word tribulation is very suggestive. It comes from a root which means 'a flail'. The thresher uses the flail to beat the wheat sheaves, that he may separate the golden wheat from the chaff and straw.
Tribulation is God's threshing--not to destroy us, but to get what is good, heavenly, and spiritual in us--separated from what is wrong, earthly, and fleshly. Nothing less than blows of pain will do this. The golden wheat of goodness in us, is so closely wrapped up in the strong chaff of sin--that only the heavy flail of suffering can produce the separation!
Many of us would never enter the gates of pearl--were it not for this unwelcome messenger, pain! "We must go through many troubles to enter the kingdom of God!" Acts 14:22 - J. R. Miller, "Miller's Year Book--a Year's Daily Readings")

If the Holy Spirit can take over the subconscious with our
consent and cooperation, then we have almighty Power working at
the basis of our lives, then we can do anything we ought to do,
go anywhere we ought to go, and be anything we ought to be.
Life is supplied with a basic adequacy...
The conscious mind determines the actions, the unconscious
mind determines the reactions; and the reactions are just as
important as the actions. Many Christians are Christians in
their actions--they don't lie, steal, commit adultery, or get
drunk; but they react badly to what happens to them--they react
in anger, bad temper, self-pity, jealousy, and envy... When the
depths are held by the Holy Spirit, then the reaction is
Christian.- E. Stanley Jones (1884-1973), Conversion, New York:Abingdon Press, 1959, p. 233,235