2 Corinthians 6:11-15

We have spoken freely to you, Corinthians; our heart is wide open. You are not restricted by us, but you are restricted in your own affections. In return (I speak as to children) widen your hearts also. Do not be unequally yoked with unbelievers. For what partnership has righteousness with lawlessness? Or what fellowship has light with darkness? What accord has Christ with Belial? Or what portion does a believer share with an unbeliever?