Is it obligatory to teach a child or an ignorant adult the Sharia rulings, taking into account the nature of the rulings and the learner's receptiveness?

It is obligatory or recommended to teach a child what he needs concerning his religion, according to the action and situation. This is based on the Almighty’s saying: "Protect yourselves and your families from a Fire," and the Prophet’s (peace be upon him) saying: "All of you are shepherds, and all of you are responsible for your flock." It has been reported that teaching a son what he needs for his religion is obligatory upon the father and all guardians, as well as upon the mother in the absence of the father. It is obligatory to denounce forbidden actions to children to discipline and educate them. It is obligatory to teach a child what validates his creed and worship, and to teach him the prohibition of fornication, sodomy, theft, drinking intoxicants, lying, and backbiting, and to inform him of his entry into legal accountability upon reaching puberty.