You're right and please pass my apologies along to the CEO in your next communication to him.
He indeed did not inject religion into the conversation. You did when you chose to post his email, which expressed a religious view: "I have always believed that God works in mysterious ways....". FWIW, I agree with his comment. Others may not, but your placement of the statement on the board (assuming he actually made it) is what precipitated the following comment by Frankiy:
"He claims to be a Christian but he doesn´t keep his word." Which strikes me as an opinion that he is entitled to have.
Perhaps the next time you choose to post a communication from the CEO of FBCD without his blessing you might want to consider the likelihood that others will comment on it.