Answer:
You don't need to believe in God to be a moral person since the natural law is written in the hearts of men. However, man is inclined to God since God is his final end and so we can only find fulfillment in God. If we want true fulfillment then, we must undertake to discover God and have faith. And in all this, it is necessary to have a conviction that God exists since you cannot take your faith seriously and realize your potential if you do not have conviction.
