Al-Qiyama (The Day of Resurrection) - Chapter 75 : Verse 6
There are people who desire to continue in their wrongdoing throughout the entirety of their lives. Although people may be aware of ultimate accountability, they put off repentance as if they are guaranteed a long life. This is an ethic exemplified by the saying, "Sow your wild oats," which advocates getting all the lewdness and sin out of one's life when one is young, and then later calming down and adopting religion. Besides the obvious error of this ethic, another terrible flaw is that people die at all ages, and some never get the chance to repent and make amends. Moreover, what kind of repentance is this when people intentionally indulge in sin banking on the possibility that later on in life - after all the energy and drive diminishes - they will turn in penitence to God? We know that God loves those who spend their youth obedient to Him and His commandments.
"Purification of the Heart" - Hamza Yusuf, pp. 90, 91