Personally I think the single most important theological understanding needed by a true follower of Christ is a complete grasp of the sovereignty of God. I don't mean complete in the sense of full. I mean complete as in balanced and in progress. A balanced theology of the sovereignty of God will be able to make (some) sense of His grace in good times and bad - God controls both, the good times of life and the bad. Simple enough, right? But highly misunderstood. I often forget that God controls it all, everything, period.
God is praised when times are good.
When was the last time however you heard the name of Jesus declared and praised immediately after news of ill will in some one's life. Or, if it happened, how was it accepted by the hearer(s)?
This blog post (We need a Gospel That Speaks to Failure) explores success and failure in this life and what response a Christian should have to both.
I say God is good ALL the time!