forbidding marriage and commanding to abstain from foods which God created to be received with thanksgiving by those who believe and know the truth.
Them that believe and know the truth ... Once again the order of trust, then knowledge, appears in the New Testament, as in "We have believed and know that thou art the Holy One of God" (John 6:69).  The knowledge that amounts to an absolute certainty is experiential in that it follows, but does not precede, belief.