Although dogged by human disobedience and sin accumulate, does not mean there was no door to improve. Since, however mounting immoral deeds of a servant, but the door of mercy is always open. Humans are given the opportunity to improve themselves. That is, with repent of their deeds that can be delivered into the abyss of hell. Repentance must be conducted in total, which is known as repentance nashuha. Prophet sallallaahu ‘alaihi wa sallam said:
كل بني آدم خطاء و خير الخطائين التوبون. رواه الترمذي
Every child adam (man) make mistakes, and the best person is guilty of repentance. 
لو أن العباد لم يذنبوا لخلق الله الخلق يذنبون ثم يغفر لهم رواه الحاكم
If the servants of God there is no sin, surely God will create another creature who sins and then forgive them. 
With repent, we can cleanse the heart from the stain has failed. For the sin of desecrating the liver, and clean it is an obligation. Prophet sallallaahu ‘alaihi wa sallam said: Verily a believer when the sin, it will be (come) one point the black spot in his heart. If he repent, leave the (deeds) and begged for forgiveness (to Allah), then his back clean. But when increasing (sin), then added black stain until it filled her heart. So why ar raan (heart cover) which has been mentioned God in His Word “By no (so), actually what they always try to shut their hearts. [Al Muthaffifin: 14] 
God also encourages us to immediately repent and beristighfar, because it so much better than soluble in sin. Allah says.
فإن يتوبوا يك خيرا لهم وإن يتولوا يعذبهم الله عذابا أليما في الدنيا والآخرة وما لهم في الأرض من ولي ولا نصير
Then if they repent, it is better for them, and if they turn away, Allah will punish them with grievous punishment in the world and the Hereafter, and they never have a protector and not (also) a helper in the earth. [At-Tauba: 74]
Prophet himself had set an example in this repentance. He sallallaahu ‘alaihi wa sallam much repent and beristighfar, to the extent that the friends count as much more than a hundred times in the majlis, as Nafi’ Maula Ibn Umar has stated:
كان انن عمريعد لرسول الله صلى الله عليه وسلم في المجلس الواحد مائة مرة من قبل أن يقوم رب اغفر لي وتب علي إنك أنت التواب الغفور رواه الترمذي
Ibn ‘Umar never count (reading istighfar) Messenger of n in a majlis before rising from her a hundred times, (which reads): Yes my Lord, forgive me and accept taubatku. Verily You are All recipients repentance, Most merciful. 
Understanding Repentance Nashuha
What is meant by repentance nashuha, is the return of a servant to God from sin ever committed, either deliberately or because of ignorance, with honest, sincere, strong and supported by the lifting of obedience-obedience of a servant reached the status of the guardians of God’s Muttaqin (cautious) and (obedience) that may be protective of the devil himself.
Law And Recommended Repentance Nashuha
Nashuha repentance law is fard ‘ayn (the duty of every individual) upon every Muslim. The evidence:
1. God’s Word:
وتوبوا إلى الله جميعا أيه المؤمنون لعلكم تفلحون
And bertaubatlah to God, O people who believe that you’re lucky. [An Nuur: 31].
يا أيها الذين آمنوا توبوا إلى الله توبة نصوحا
O ye who believe! Bertaubatlah to Allah with sincere repentance pure. [At Tahriim: 8].
2. Word of the Prophet sallallaahu ‘alaihi wa sallam.
ياأيها الذين ءامنوا توبوا إلى الله فإني أتوب إلى الله في اليوم مائة مرة. رواه مسلم
O, the believers. Bertaubatlah to God, because I also confess to God a hundred times a day. 
Muslims also agreed to the obligation of repentance, as claimed Al-Qurtubi: “(The scholars) the people have consensus (agreement) that the law of repentance is fard (obligatory) on all believers” . Ibn Qudama also stated thus .
GRACE OF GOD breadth of repentance and virtue NASHUHA
Humans should not worry if repentance is not accepted, because God’s grace is vast, as the prayer of the angels described role in His Word:
ربنا وسعت كل شيء رحمة وعلما فاغفر للذين تابوا واتبعوا سبيلك وقهم عذاب الجحيم
Our Lord, the grace and knowledge encompasses all things thou, grant forgiveness to those who repent and follow Thy Path and guard them from the torment of a fiery hell. [Al-Mu’min: 7].
TERMS repentance NASHUHA
So that repentance can be accepted nashuha Allah, there are several requirements that must be fulfilled:
Repentance is acceptable only from a Muslim. As for the unbelievers, then repentance is to enter Islam. Allah says.
وليست التوبة للذين يعملون السيئات حتى إذا حضر أحدهم الموت قال إني تبت الآن ولا الذين يموتون وهم كفار أولئك أعتدنا لهم عذابا أليما
And are not repenting it is acceptable to God than those who do evil (which) until when death comes to one of them, (then) he said “Verily I repent now.” And not (also accepted repentance) those who die are those in disbelief. For people that already have prepared a painful punishment. [An-Nisa ‘: 18].
Repentance accepted the Shari’ah is based on the sincerity. Repentance by riya `or worldly purposes, not said to be repentance syar’i. Allah says.
إلا الذين تابوا وأصلحوا واعتصموا بالله وأخلصوا دينهم لله فأولئك مع المؤمنين وسوف يؤت الله المؤمنين أجرا عظيما
Except those who repent and amend and hold fast to the (religion) of Allah and sincere (to do) their religion for God. So they were together those who believe and someday God will give to those who believe a great reward. [An-Nisa ‘: 146].
3. Confessed his sin.
Repentance is not valid, except after knowing the sin and admit mistakes, and expect to survive the adverse effect such actions.
4. Full of remorse.
Repentance can only be accepted with deep expressions of remorse. Prophet sallallaahu ‘alaihi wa sallam said:
الندم توبة رواه ابن ماجه
Remorse is repentance. 
5. Leaving disobedience and restore rights to their owners.
People who must leave kemaksiatannya repent and return any rights to its owner, if a property or the like. If the form of libel or the like, then by way of apology. If a ghibah (wag), then by way of pleading permissible (tolerable) for those applications will not cause other adverse effects. If it turns out bad implications, it is sufficient to pray for him to achieve the good.
6. Repent period before the breath was in the esophagus (breathe death) and before the sun rises in the west.
Prophet sallallaahu ‘alaihi wa sallam has explained in words he sallallaahu’ alaihi wa sallam:
إن الله يقبل توبة العبد ما لم يغرغر. رواه الترمذي
Verily Allah accepts repentance of a servant before his breath in the esophagus .
الهجرة لا تنقطع حتى تنقطع التوبة ولا تنقطع التوبة حتى تطلع الشمس من مغربها. رواه أبو داود وأحمد
Hijrah is not interrupted until the cessation of (time to) repentance, and repentance is not interrupted until the sun rises in the west .
7. Istiqamah after repent.
فاستقم كما أمرت ومن تاب معك ولا تطغوا إنه بما تعملون بصير
Then keep you on the right path, as commanded, and (also) those who have been with you repent and do not transgress limits. He is Seer of what ye do. [Huud: 112].
8. Make amends after repentance.
وإذا جاءك الذين يؤمنون بآياتنا فقل سلام عليكم كتب ربكم على نفسه الرحمة أنه من عمل منكم سوءا بجهالة ثم تاب من بعده وأصلح فأنه غفور رحيم
If those who believe in Our revelations came unto you, then say “Peace be unto you. Thy Lord has set for Himself mercy, (namely) that whoever among you does evil in ignorance, then he repented after work and make repairs, then surely Allah is Forgiving, Merciful. [al-An `am: 54].
TO REMEMBER WHEN repent
1. Convinced that God is knowing, all-seeing. God knows all the hidden and concealed in the heart. Although we do not see it, but He must have seen it.
2. See the majesty of your Essence durhaai, and do not see the small object immoral, as his word.
نبئ عبادي أني أنا الغفور الرحيم وأن عذابي هو العذاب الأليم
Tell to My servants that I am actually the Oft-Forgiving, Most Merciful, and that the real azabKu is a painful doom. [Al-Hijr: 49-50].
3. Remember, that sin is all bad and bad, because he is an obstacle to achieving happiness in the world and the hereafter.
4. Abandoned places disobedience and friends who behave badly, who used to help her sin, and cut off ties with them as long as they have not turned good.
THINGS hinder repentance
Among the things that hinder sin is:
1. Heresy in religion. Prophet sallallaahu ‘alaihi wa sallam said:
إن الله حجب التوبة عن صاحب كل بدعة
Surely God closes repent of all experts heresy. [Ash-Saheehah No. 1620]
2. Alcoholism. Prophet sallallaahu ‘alaihi wa sallam said:
من شرب الخمر لم تقبل له صلاة أربعين ليلة فإن تاب تاب الله عليه فإن عاد كان حقا على الله تعالى أن يسقيه من نهر الخبال قيل وما نهر الخبال قال صديد أهل النار رواه أحمد
Those who drink The wine (liquor), then his prayer is not accepted for forty nights. If he repent, God will accept it. However, when repeated, it is worth when God gave him a drink from the river Khibaal. Someone asked: “What is a river Khibaal?” He replied, “Pus inhabitants of hell. 
Thus a brief treatise on repentance nashuha. Hopefully we can be a reminder to always repent to Allah Subhanahu wa Ta’ala.
[Copied from the magazine edition of As-Sunnah Foundation 01/Tahun IX/1426H/2005M Published Lajnah Istiqomah Surakarta, Jl. Solo – Purwodadi Km. 8 Selokaton Gondangrejo Solo 57 183 Tel. 08121533647, 08157579296]
. This treatise summarized by Ustadz Kholid Syamhudi of At-Tauba An Nashuh, the work of Sheikh Salim bin Id al-Hilali, publisher of Al-Islamiya Al Maktabah Jordan and Beirut, Dar Ibn Hazm, Ed. III, Th. 1413 H.
. HR At-Tirmidhi, no.2499 and dihasankan Al-Albani in Saheeh al-Jami ‘Ash Sagheer, no. 4391.
. HR Al-Hakim, pp. 4 / 246 and classed as saheeh al-Albani in Lineage Saheehah, no. 967.
. Hadeeth of Ibn Majah, no. 4244 and dihasankan Al Albani in Saheeh al-Jaami ‘no. 1666.
. HR At-Tirmidhi, no. 3434 and classed as saheeh al-Albani in Lineage Saheehah, no.556.
. Muslim (17/24) with Sharh Nawawi, from the hadeeth of ‘Abdullah ibn’ Umar.
. Al Jaami ‘Li Ahkam Al Qur `an (5 / 90).
. Mukhtasar Minhaaj Al Qashidin, pp. 322.
. Ibn Majah, no. 4252 and Ahmad no. 3568 and others. Al-Albani was classed as saheeh hadeeth in Saheeh Al Jaami ‘al-Sagheer, no. 6678.
. HR At-Tirmidhi no. 3537 and dihasankan Al Albani in Saheeh al-Jami ‘Ash Sagheer no.1899.
. Reported by Abu Dawud, no. 2479 and Ahmad in Musnad (3 / 99) and classed as saheeh in Saheeh al-Jami ‘, no. 7469.
. Reported by Ahmad (2 / 189) and classed as saheeh al-Albani in Saheeh al-Jaami ‘Ash Sagheer, no. 6188