Read: Leviticus 18
No one is to approach any close relative to have sexual relations. I am the Lord. Lev 18:8
Next to the preservation of life the most powerful human drive is sex. Sex, as we are beginning to understand these days, is like a great river which, when it flows quietly between its banks, is a boon and a blessing to us. But when it is raging in full flood, inundating the landscape in permissiveness and promiscuity, it is terribly destructive and hurtful. God’s Word is careful to regulate us and help us in this area. It is amazing that God takes the risk of letting us have this fantastic power in our lives. He doesn’t take sex away from us if we misuse it. He takes that risk with us, with a plea to us that we learn to keep it within its banks.
You can see how God underscores the purpose of these instructions. They are to make you live, not die — not be restricted, not narrowed and hemmed in and prohibited from expressing yourself. No, quite the contrary! They are there so that you might live, might enjoy life to the fullest degree, might find it whole and rich.