It is part of human nature to be heedless, make mistakes and have shortcomings, but it is from the mercy of Allah The Almighty that He opened the gate of repentance and commanded us to turn towards Him whenever sins overwhelm us. If it were not for this road to repentance, humanity would have been unable to gain closeness to Allah The Almighty and would have lost hope in repentance and forgiveness.
The path of repentance is the way towards salvation and success; it is open for each one of us. Allah The Almighty called upon all His slaves, both believers and disbelievers to repent, and He informed that He forgives all sins for those who repent regardless of the extent and greatness of these sins, Allah The Almighty Says (what means): {Say: “O My slaves who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allah, verily, Allah forgives all sins. Truly, He is Oft-Forgiving, Most Merciful.”} [Quran 39:53]
No one knows when he will die or how much time he has left in this worldly life; it is sad to see some people delaying repentance saying: "We still have plenty of time left. Let us enjoy our life while we are young and when we become old we will repent." Such thoughts are from the whispers of Satan and following the desires of this vanishing life. Satan promises man while he has no power to grant man anything. Therefore, you should hasten towards repentance, and beware of heedlessness, delaying, and feeling that you still have a long life to live.
Hasten to repentance and beware of delaying repentance, because delaying, itself, is a sin that needs repentance. Immediate repentance from sins is mandatory, so repent before death; repent before the time will come and regret will not benefit you. You do not know when your life will end. Repent before the darkness overwhelms your heart and sins become a habit. Repent before you become sick and then die without getting the chance to repent.
Some people commit sins flagrantly and disobey Allah The Almighty, and when you try to talk to them about repentance they say, "There are many people who openly disobey Allah The Almighty day and night and their sins are so numerous that they may be uncountable, yet they are very rich and healthy, thriving with the favors of Allah The Almighty upon them." Those who say such things forget that Allah The Almighty grants these worldly gains to the people Whom He loves and Whom He does not love. This could be a way of gradually punishing them. Although the punishment of Allah The Almighty might be delayed for them, but when He does punish them it is severe. The Prophet said: “If you see that Allah Has bestowed favors upon someone although he is sinning, then know that it is a way of gradually punishing him." Then he recited the verse in which Allah The Almighty Says (what means): {So, when they forgot (the warning) with which they had been reminded, We opened for them the gates of every (pleasant) thing, until in the midst of their enjoyment in that which they were given, all of a sudden, We took them (in punishment), and lo! They were plunged into destruction with deep regrets and sorrows. So the root of the people who did wrong was cut off. And all the praises and thanks are to Allah, the Lord of the `Aalameen (mankind, jinn, and all that exists).} [Quran 6:44-45]” [Ahmad]
All you have to do is approach the path to repentance and set out upon it, and you will find the response as Allah The Almighty Says (what means): {And verily, I am indeed forgiving to him who repents, believes (in My Oneness, and associates none in worship with Me) and does righteous good deeds, and then remains constant in doing them (till his death).} [Quran 20:82]