Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness?
–2 Corinthians 6:14. NKJV
The Gods Word Translation makes it really clear-
Stop forming inappropriate relationships with unbelievers. Can right and wrong be partners? Can light have anything in common with darkness?
–2 Corinthians 6:14 GWT