All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
It is very clear that what that man said to you is a comment on your actions and not on the content of that material, so he is neither mocking the religion nor apostating from Islam. It is not a simple matter to declare someone as a kaafir (a non-Muslim, disbeliever) because this means him going out of the fold of Islam and applying the rulings of apostasy on him; so he would be separated from his wife, be killed for apostasy, the funeral prayer would not be offered for him, he would not be enshrouded and not be buried in the Muslim graveyards, and so forth.
So the matter is very serious. If it is confirmed with certainty that someone is a Muslim, then his leaving the religion cannot be confirmed except with the same certainty. Therefore, the scholars stated that a statement or an act may constitute disbelief but its doer is not ruled to be a disbeliever except after certain conditions are met while there are no impediments for declaring him a disbeliever, as we have already explained in fatwa 91677.
That person's objection to what you do is not justified, as these social media are one of the best means by which goodness is propagated and people are made aware of the religion and called to Allaah. If morality is not spread through these media, then are they to be left for the spread of evil, immorality and debauchery? So, what that man said to you is not reasonable. You should continue doing what you are doing; may Allaah enable you to do good and reward you for it. Indeed, the Prophet said, "I swear by Allaah! If Allaah guides one single man (to Islam) by your efforts, then that will be better for you than possessing an abundant number of red camels (a very expensive breed of camels that was considered the most valuable property in the sight of the Arabs)." [Al-Bukhari and Muslim]
Allaah knows best.