Check out this awesome video that explores the reasons why Christians think it’s alright to date non-Christians. For your reference, the video will be going through 2 Corinthians 6:14-18, and Deuteronomy 22:10.
2 Corinthians 6:14-18
14 Do not be yoked together with unbelievers. For what do righteousness and wickedness have in common? Or what fellowship can light have with darkness? 15 What harmony is there between Christ and Belial? What does a believer have in common with an unbeliever? 16 What agreement is there between the temple of God and idols? For we are the temple of the living God. As God has said: “I will live with them and walk among them, and I will be their God, and they will be my people.”
17 “Therefore come out from them
and be separate,
says the Lord.
Touch no unclean thing,
and I will receive you.
18 “I will be a Father to you,
and you will be my sons and daughters,
says the Lord Almighty.”
10 Do not plow with an ox and a donkey yoked together.