Repentance is a very precious gift from Heaven which allows us to rectify previous misdeeds. One should not take this gift lightly as it can be taken away.
A person who repeatedly ignores the Almighty’s warnings could find the doors of repentance locked when he’s ready to change his ways.
Don’t say “one day I’ll repent”, you might not get that opportunity. 
When the imminent redemption arrives, the gates of repentance will close for eternity. Act now before it’s too late and save yourself, your friends and your family.

“G-d warns a man once, twice, even three times. If, at that point, he does not repent, G-d locks the doors of repentance against him to ensure that he will be punished for his sin.” Midrash