See what the Bible says about it.

If anyone says, "I love God," and yet hates his brother or sister, he is a liar. For the person who does not love his brother or sister whom he has seen cannot love God whom he has not seen.

– 1 John 4:20

But the person without the Spirit does not receive what comes from God's Spirit, because it is foolishness to him; he is not able to understand it since it is evaluated spiritually.

– 1 Corinthians 2:14

'The one who sleeps with his sister, whether his father's daughter or his mother's daughter is cursed.' And all the people will say, 'Amen!'

– Deuteronomy 27:22