What is my duty towards my child, born to an Arab man before my conversion to Islam, and how should I deal with the reality of his lineage in front of him and in front of people, and is it obligatory to inform them of that?

Adultery is a forbidden crime, and its perpetrator is punished in this world and the Hereafter, unless he repents and turns to God, for the door of repentance is open. A child born of adultery follows its mother and is not attributed to the father. It must be raised according to Islamic morals. The mother must repent and conceal the matter. If the child insists on knowing the truth, he can be told that what happened was before Islam and repentance erases what came before it, and that the child bears no responsibility for what occurred, and contentment with divine decree and destiny is obligatory.