I apostated more than three times when I was young and now I want to be firm on islam but recently I read that in the tafsir of Ibn Kathir from ali (ra) that istitaba of Murtad is three times and after he is killed basing himself on an ayat in surat Al Nissa. Does it means that after three apostasy Allah does not forgive the apostate if he makes Tawba. What must I do now.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

If by being young you refer to the age below puberty [which means before being Islamicly held accountable for your deeds], then the jurists differed in opinion about the ruling on the apostasy of a boy who can use his own intellect in reasoning, some of them are of the opinion that his apostasy is considered while other jurists are of the view that it is not. The second opinion is the most preponderant opinion because the Prophet said: "The pen is lifted (stops from recording deeds) from three kinds of people: a sleeping person until he wakes up, a child until he reaches the age of puberty and an insane person until he starts reasoning." [Abu Daawood, At-Tirmithi, An-Nasaa’i and Ibn Maajah]

However, if we presume that his apostasy is taken into account, or that the apostasy took place after he became pubescent, then whoever repents Allaah accepts his repentance; for more benefit, please refer to Fatwa 88067.

Therefore, you should take the initiative to repent, to be steadfast on the obedience of Allaah, to be keen on acquiring Islamic knowledge and performing good deeds, to keep company with righteous people and avoid keeping company with dissolute people, and to stay away from any reason which may lead you to apostate again.

We ask Allaah to make us firm with the firm word (The testimony that None has the right to be worshipped except Allaah and that Muhammad is the Messenger of Allaah) in this worldly life and in the Hereafter.

As regards what Imaam Ibn Katheer said about the issue of asking an apostate to repent, it is in regard to the person who insists on his apostasy and not in regard to a person who wants to repent.

Allaah Knows best.