“If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him. But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind. That man should not think he will receive anything from the Lord; he is a double-minded man, unstable in all he does.”
Søren Kierkegaard wrote a book called Purity of Heart Is to Will One Thing. I’ve not read it yet, but I’m fascinated by the title. He puts the two things at odds: Double-mindedness is the opposite of a pure heart. A double-minded man wills many things – fortune, fame, comfort… the man who has a pure heart wills for God to be glorified.
Look:
- Who shall ascend the hill of the Lord?
- And who shall stand in his holy place?
- He who has clean hands and a pure heart,
- who does not lift up his soul to what is false,
- and does not swear deceitfully.
- (David)
- Draw near to God and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you men of double mind.
- (James)
You shall love the Lord your God with all your heart.
(Jesus)

who said that?