2 Corinthians 6:14-7:1 reads:
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? What agreement has the temple of God with idols? For we are the temple of the living God; as God said,“I will make my dwelling among them and walk among them, and I will be their God, and they shall be my people. Therefore go out from their midst, and be separate from them, says the Lord, and touch no unclean thing; then I will welcome you, and I will be a father to you, and you shall be sons and daughters to me, says the Lord Almighty.”
Since we have these promises, beloved, let us cleanse ourselves from every defilement of body and spirit, bringing holiness to completion in the fear of God.
This passage is often referenced in relation to how Christians should approach marriage to an unbeliever. However, it also referenced by some in relation to how Christians should approach their dealings with unbelievers regardless of the context. In the minds of some, Christians should never form a partnership of any kind (be “yoked”) with an unbeliever. If we attempt to apply this understanding of the passage, is it even possible?
When we vote, are we not “partnering” at some level with those we vote for (either the candidate or the party)? What about when we make a political contribution? What if we sign a petition protesting a political point (e.g. abortion, gay marriage, etc.)? Do we need to be sure that the political candidates, parties, and other signatories are all from the same theological belief system as we are?
What about when we take a job? Does our boss need to be a Christian? What about all of our co-workers? If we are athletes, do all of our teammates and coaches have to be Christians to not violate 2 Corinthians 6:14-7:1?
I think you get my point. It is impossible to apply this passage to every relationship / partnership that a Christian has. It is not intended to be applied this way.
So then, what is the correct application? The key to understanding this passage correctly lies in verse 7:1. It is about maintaining holiness. Christians are to avoid those relationships that have a potential to hinder their walk with God and influence their moral decisions. Believers can have parnterships with unbelievers in any area where this type of influence does not exist.