Kierkegaard and Christianity - Belief or a Means to Change Existence?

Have not been able to do any sustained reading these past few weeks. A couple of nights ago I picked up John Caputo's book on How to Read Kierkegaard. Forty years ago when they talked about him in school, I had absolutely no interest and no regard for him as he was emotional, subjective, and mushy. But I've changed. I'm fighting to get out of the robot rationalism of my younger days of , say, before age 50.

Caputo in one place has this pithy thing to say. He says that K, and these are Caputo's words

"had written that Christianity is not a doctrine supported by evidence but a command to transform existence that can only be witnessed."