Dear questioner,
May Allah bless you and increase you in good.
Forgiveness and Mercy
True repentance entails leaving that particular sin immediately and not intending to return to it. If one has not done this, then it is not true repentance.
We as human beings are prone to commit sins even daily. The Prophet ( peace and blessings be upon him) knew this when he said, “All of the children of Adam commit sins, but the best of sinners are those who repent often.” [Tirmidhi]
However, we can gradually improve and strengthen our faith. We also must keep in mind that success comes from Allah.
“My success lies only with God. In Him I trust, and to Him, I turn.” [Quran 11:88]
Rely upon Allah
Remember that Allah is the one who makes it easy to perform good deeds. Therefore ask Allah for guidance and persist in doing good deeds until the door of ease and success opens up for you. That is a daily endeavor and perhaps a lifelong struggle.
Hope and Fear
The balance every believer should possess is one of hope and fear. These are the two wings of the believers.
Sayyidina Anas narrated that the Prophet (peace and blessings be upon him) entered upon a young man who was dying and said: “How do you feel?” He said: “I have hope in Allah, O Messenger of Allah, but I fear my sins.” The Messenger of Allah (peace and blessings be upon him) said: “These two things (hope and fear) do not coexist in the heart of a person in a situation like this, but Allah will give him that which he hopes for and keep him safe from that which he fears.” [Ibn Majah]
We have many traditions that point to us the vast mercy of Allah. We also know that Allah can punish us for our sins; therefore, we must always remain repentant and fearful. That is the comportment [adab] with Allah.
Shahada and Returning to Sins
A person who says their shahada but then afterward commits sins is like any other convert. It is bound to happen. They follow the same steps as other believers when wanting to repent. Everything I mentioned will also apply to converts the same way. That is because he/she is now a regular Muslim. Therefore, whenever they commit sins, they need to repent like all other Muslims.
Finally, remember that we are not commanded to be perfect but rather to return to Allah often and constantly ask for His forgiveness.
“Surely Allah loves those who always turn to Him in repentance and those who purify themselves.” [Quran 2:222]
Allah knows best.
[Imam] Yama Niazi
Checked and Approved by Shaykh Faraz Rabbani