Or do you not know that he who is joined to a harlot is one body with her? For “the two,” He says, “shall become one flesh.” But he who is joined to the Lord is one spirit with Him. Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body. Or do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own? 1 Corinthians 6:16–19

Jesus answered, “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.” John 3:5–6