If a believer truly repents to Allah The Almighty and frees himself from the injustice between him and other people, and if he rectifies his relations with them, there can be nothing better for him. No doubt, as a narration says: "Dissonance between people is the shaver. I do not say that it shaves the hair, but I say that it shaves (destroys) the religion." [At-Tirmithi] How could one enter Ramadan with his religion shaved? How could he enter, seeking forgiveness, given that he is still a wrongdoer who has not repented, but rather, is overburdened with sins, misdeeds, mistakes and crimes?
If he repents in those days, he will come out of Ramadan with repentance, having obtained forgiveness. If he starts with repentance, and then performs standing in prayer with which he comes out of Ramadan, he will come out, having (the reward of) standing in prayer, and (the same applies to) fasting, Thikr, (remembrance of Allah The Almighty) recitation of the Quran, acts of worship, longing and affection for his Lord. However, if he enters with sin, he will come out with sin; and if he enters with negligence, he will come out with negligence. This is something that one should understand, because of which a person returns, after Ramadan, to the same bad conduct before Ramadan, unless he is overtaken by the mercy of Allah The Almighty for another reason.
If believers are driven by the desires of their own selves, by the whispers of the devil and one's evil inclinations, this will be reflected back to themselves and their deeds, and increase the disease that lies in their own selves, desires, leanings and inclinations. The believers should know that Allah The Almighty never wrongs them even in the least, and that they deserve nothing from Him. Let them return upon themselves with that, which reads: "Disgraced is the one who witnesses Ramadan and it is over before he is forgiven." [At-Tirmithi] Let them also strive against themselves in those days, where the gate of supplication is opened for them, perchance all of this will rise, by the permission of Allah The Almighty.
Let one reflect upon his sins and misdeeds, and the extent to which he is heedless and negligent, and not ready for the Hereafter, having indulged in this world. He will see himself deceived in this world, having forgotten the Hereafter, rather seeking the world, loving its desires and pleasures, and being possessed by heedlessness: then, how could his supplication be answered? If he falls into sin, misdeeds and mistakes, how could this heart meet Allah The Almighty, and have its meeting and presence with the Lord a cause of response to supplication?
If Allah The Almighty endows you with repentance, you should be sincere and true in your determination to achieve forgiveness. The sign of this truthfulness is to strive to realize two things, as a means to blot out sins. That is the same meaning referred to by the Messenger of Allah in his saying: "Both fasting and the Quran will intercede for the slave (who observes fast and recites the Quran) on the Day of Judgment. Fasting will say, ‘I prevented him from drink, food and sexual desire.’ The Quran will say, ‘I prevented him from sleep. So, accept my intercession for him.’ Thus, the intercession of both will be accepted." [Ahmad]
Most of us do not bear these two meanings in mind. That is, two kinds of striving are combined in the fasting of Ramadan: to strive (by fasting) during the day, and to strive (by standing in prayer) at night.
To strive by fasting during the day requires fulfilling one's fasting with which he attains forgiveness and is emancipated from Hell. This should be done well, i.e. fasting should be a means to prevent one from prohibitions and desires, and cause him to approach his Lord The Almighty with Athkaar (words of remembrance and supplication) and acts of obedience. In other words, if one meets all the conditions of this fasting which has prevented him from what is unlawful such as useless talk, hearing, seeing, prohibited earnings, and prohibited desires of food, drink and sexual intercourse, it will be a cause of forgiveness; and if he observes fasting according to the conditions because of which Allah The Almighty removes sins, it will be a cause of intercession on the Day of Judgment.