These quotes are from the Christian classic Knowing God by J.I. Packer. It is a must-read for all believers.
“What makes life worthwhile is having a big enough objective, something which catches our imagination and lays hold of our allegiance, and this the Christian man or woman has, in a way that no other man or woman has. For what higher, more exalted, and more compelling goal can there be than to know God?”
“Men who know their God are before anything else men who pray, and the first point where their zeal and energy for God’s glory come to expression is in their prayers…. If there is little energy for such prayer, and little consequent practice of it, this is a sure sign that as yet we scarcely know our God.”