We don't always understand at the time, but God will allow us to go through a valley so we can comfort others in the same valley in the future.
2 Corinthians 1:3-4 Blessed be God, even the Father of our Lord Jesus Christ, the Father of mercies, and the God of all comfort; 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.
The good Lord often comforts me with a gospel song like "The God On The Mountain is Still God In The Valley” (Lynda Randle, You Tube) and “Amazing God”--- “I still serve an amazing God, He’s been with me every mile my weary feet have trod . . .” (Triumphant Quartet, YouTube).