What is the meaning of "And had your Lord willed, those on earth would have believed - all of them entirely," and the interpretation of Allah's saying, "And it was not for any soul to believe except by permission of Allah," and how can one respond to the misconceptions of Christians related to this meaning?

These verses are a consolation to the Prophet, peace and blessings be upon him, and affirm divine will, and that all matters are in the hands of Allah, so nothing occurs except what He has decreed and predestined. For if Allah had willed the faith of all people on earth, they would have believed. And it is not for any soul to believe except by the permission, will, and knowledge of Allah. And no one can compel people to believe if Allah does not intend that for them.