One of the most dangerous lies of the devil is the one that tells us to delay our repentance to another day. This is a huge temptation and can lead us into a deeper mess. He will tell us to wait until tomorrow or wait until our Confession to change.
This is wrong. We must never allow these diabolic voices to interfere with our spiritual progress. If you are struggling with a particular sin, don't put off your repentance. Start now.