While most of the reasons listed below are plucked directly from the Bible (and therefore in language that is familiar to us), seeing them all piled together and thinking over the sheer gravity of what is entailed by these truths should cause us to do exactly what Piper wants us to do - to leap for joy!
From John Piper's new book, Finally Alive.
The aim in this list is to give us an accurate diagnosis of our disease so that when God applies the remedy at great cost to himself, we will leap for joy and give him some measure of the glory he deserves. We will not sing with authentic amazement the words "Amazing grace, how sweet the sound that saved a wretch like me," unless we know the nature of our "wretchedness."
1) Apart from the new birth, we are dead in trespasses and sins (Eph. 2:1-2).
2) Apart from the new birth, we are by nature children of wrath (Eph. 2:3).
3) Apart from the new birth, we love darkness and hate the light (John 3:19-20).
4) Apart from the new birth, our hearts are hard like stone (Ezek. 36:26; Eph. 4:18).
5) Apart from the new birth, we are unable to submit to God or please God (Rom. 8:7-8).
6) Apart from the new birth, we are unable to accept the gospel (Eph. 4:18; 1 Cor. 2:14).
7) Apart from the new birth, we are unable to come to Christ or embrace him as Lord (John 6:44, 65; 1 Cor. 12:3).
8) Apart from the new birth, we are slaves to sin (Rom. 6:17).
9) Apart from the new birth, we are slaves of Satan (Eph. 2:1-2; 2 Tim. 2:24-26).
10) Apart from the new birth, no good thing dwells in us (Rom. 7:18).
11) Without the new birth, we won't have saving faith, but only unbelief (John 1:11-13; 1 John 5:1; Eph. 2:8-9; Phil. 1:29; 1 Tim. 1:14; 2 Tim. 1:3).
12) Without the new birth, we won't have justification, but only condemnation (Rom. 8:1; 2 Cor. 5:21; Gal. 2:17; Phil. 3:9).
13) Without the new birth, we won't be the children of God, but the children of the devil (1 John 3:9-10).
14) Without the new birth, we won't bear the fruit of love by the Holy Spirit but only the fruit of death (Rom. 6:20-21; 7:4-6; 15:16; 1 Cor. 1:2; 2 Cor. 5:17; Eph. 2:10; Gal. 5:6; 2 Thess. 2:13; 1 Pet. 1:2; 1 John 3:14).
15) Without the new birth, we won't have eternal joy in fellowship with God, but only eternal misery with the devil and his angels (Matt. 25:41; John 3:3; Rom. 6:23; Rev. 2:11; 20:15).