John Piper

Without the sovereign, life-giving, blindness-removing, heart-illumining, glory-revealing work of God’s Spirit, preaching, as expository exultation, cannot achieve its aims—indeed it cannot exist.

Treating Christ crucified as the decisive ground, and Christ glorified as the final goal, of every good offered to us in the Old Testament is not an encouragement to preach speculative types and shadows from grapes and twigs. It rests on solid, clear, biblical considerations relating to all Old Testament Scripture.

God gets glory from his creatures in worship by our knowing him truly, and by our enjoying him duly. Where knowledge of God is defective, his glory will be diminished in our defective knowing. Where delight in God is restrained or hindered or discouraged, his glory will be diminished in our diminished enjoyment.