Praise be to Allah.An illegitimate child does not bear any sin because of his parents’ having committed the sin of zinaa (unlawful sexual intercourse), because that was not of his doing. They bear their own sin, because Allaah says (interpretation of the meanings):
“… He gets reward for that (good) which he has earned, and he is punished for that (evil) which he has earned…” [al-Baqarah 2:286]
“… no bearer of burdens shall bear the burden of another…” [al-An’aam 6:164]
With regard to his ultimate destiny, the illegitimate person is like anyone else: if he obeys Allaah and does righteous deeds, and dies as a Muslim, then Paradise will be his; if he disobeys Allaah and dies as a kaafir, then he will be one of the people of Hell. If he mixes righteous deeds and bad deeds, and dies as a Muslim, then his fate is up to Allaah: if He wills, He will forgive him, if He wills, He will punish him, and his eventual admission to Paradise will be by the Grace and Mercy of Allaah. As for the hadeeth which says that an illegitimate person will not enter Paradise, this is a fabrication (falsely attributed to the Prophet SAWS (peace and blessings of Allaah be upon him)). And Allaah knows best.