If our formulas were one hundred percent reliable, we wouldn't need faith, we wouldn't need a living, dynamic relationship with the Lord. Instead of trusting God, we could trust the formulas. But then our belief would become wooden, our growth would come to a halt, and our spirits would become stale. God doesn't work with formulas. Neither does life.
Life is much too messy and ambiguous to be controlled and understood through formulas.
I've read books that say the answer to every life situation is to praise God. If your best friend dies, praise God. If your children are going hungry, praise God. If only life were that simple. Of course, sometimes we should praise God.