Those who abstain from the great sins and shameful deeds except a thought in mind, indeed your Lord is wide forgiving, He knows you well when He created you from the earth and when you were hidden in the bellies of your mother, so you don’t purify yourselves, He knows best the one who is heedful.
The sins done deliberately knowing the soul are included in the heinous sins. Except the thought in mind means a thought came to do a shameful deed, but is not brought in practice. That means by thinking in mind only, it won’t be included in great sins. But it should not lead to sin. See explanation 4: 31-32. ‘Indeed your Lord is wide forgiving’ means even though great sins happen from one before getting Adhikr which distinguishes good and evil, but he by identifying the sins from Adhikr if seeks forgiveness to Allah for it and gives enough ransom, then the Merciful Lord Allah will forgive the sins to him. See explanation 25: 68-72; and 39: 53-55.
It is the Three Time Knower Lord who created the heavens, earth and all in between them including mankind in six days has decided in which country, in which era, in which parents, in which sex and in which shape everyone should take birth. So you shouldn’t purify yourselves. That means you shouldn’t act as pious before others hiding your sins and offences, you shouldn’t be brag, and there shouldn’t be a condition of forgetting the Lord at any time, and anywhere. But by transforming his/her Jinn soulmate in to believer utilising Adhikr-the Three Time Knowledge, as well as Food, Clothe and Sight of human soul-everyone should purify himself/herself. It is possible only by confirming himself as believer, conceive the character of Impartial Lord and thus free from the covetousness of the soul, and conveying the Message of Lord Adhikr to entire mankind. Then only he/she becomes approving Allah as Impartial who taught the mankind Adhikr. See explanation 4: 49-50; 7: 178; and 36: 6, 19.