Chastisement comes directly from God for correction while trial comes from Satan with God's permission for character building. Read the book of Job for the ultimate trial. Job speaks to the struggling faith of the sufferer. In effect he says to the Godly sufferer, "Forget the logical arguments spun out by those who sit together at their ease and discuss the ways of God, and forget those voices in your own heart that are little more than echoes of their pronouncements. Let me tell you a story."
Trial is our controlled exposure to the enemy which trains us to be mature believers and counselors.
1 Corinthians 10:13 There hath no temptation taken you but such as is common to man: but God is faithful, who will not suffer you to be tempted above that ye are able ; but will with the temptation also make a way to escape, that ye may be able to bear it.
2 Corinthians 1:3 Blessed be God, even the Father of our Lord Jesus Christ, the Father of mercies, and the God of all comfort; 4 Who comforteth us in all our tribulation, that we may be able to comfort them which are in any trouble, by the comfort wherewith we ourselves are comforted of God. 5 For as the sufferings of Christ abound in us, so our consolation also aboundeth by Christ. 6 And whether we be afflicted , it is for your consolation and salvation, which is effectual in the enduring of the same sufferings which we also suffer : or whether we be comforted , it is for your consolation and salvation.