Unequally Yoked

But if the unbelieving partner leaves, let him leave. In such cases the [remaining] brother or sister is not [spiritually or morally] bound. But God has called us to peace.

Do not be unequally bound together with unbelievers [do not make mismatched alliances with them, inconsistent with your faith]. For what partnership can righteousness have with lawlessness? Or what fellowship can light have with darkness?

holding to a form of [outward] godliness (religion), although they have denied its power [for their conduct nullifies their claim of faith]. Avoid such people and keep far away from them.