When does the call to Allah cease to be an obligation upon the individual Muslim, and if it does not cease, what are the means that can be followed?

The call to God is not lifted from a responsible Muslim today. He must call to God with whatever he can and knows, for the Prophet, peace and blessings be upon him, said: "Convey from me, even if it is a single verse." This call must be based on knowledge and insight, for Allah Almighty says: "Say, 'This is my way; I invite to Allah with insight, I and those who follow me.'" This does not mean that one should not call to God until he becomes a scholar; rather, what is required is knowledge of the issue being called to, what relates to it, and the condition of the one being called.