Kierkegaard, thinking of James 4:8, says purity of heart is willing one thing. like this:
purify hearts, ye two-souled!
clear your minds, you doubters.
purify your hearts, you double-minded
put away deceit from your hearts, you false in mind.
make your hearts pure, you who are half-hearted towards God.
what's the only thing, there's all too little of?
enter size metaphors, which are more real than their anchors. Ask Will Sherwin (415 695 1605) how big his heart is. That's a basis-vector-- measure the world with it)
Did continue by reasoning thus: to be not-half-hearted means to will just one thing. to will one thing only, is to will the Good, no other is possible. and not just that but a specific Good: the Good in truth. because the others are all too small! can I only meet him when the biggest thing I can think of is still too small?
good is fun, but fun isn't often the good in truth, and some of us get confused