Can two walk together, except they be agreed? Amos 3:3
The wife of Lot was a selfish, irreligious woman, and her influence was exerted to separate her husband from Abraham. But for her, Lot would not have remained in Sodom, deprived of the counsel of the wise, God-fearing patriarch. The influence of his wife and the associations of that wicked city would have led him to apostatize from God had it not been for the faithful instruction he had early received from Abraham. The marriage of Lot and his choice of Sodom for a home were the first links in a chain of events fraught with evil to the world for many generations.
No one who fears God can without danger connect himself with one who fears Him not. "Can two walk together, except they be agreed?" (Amos 3:3). The happiness and prosperity of the marriage relation depends upon the unity of the parties; but between the believer and the unbeliever there is a radical difference of tastes, inclinations, and purposes. They are serving two masters, between whom there can be no concord. However pure and correct one's principles may be, the influence of an unbelieving companion will have a tendency to lead away from God. (Patriarchs and Prophets, 174)
Reflection: This verse applies to all of our relationships. Do you have an unbelieving spouse or friend? Pray for him or her to accept Jesus and experience the beautiful life that only He can give. Another point that is vital to our safety is that we don't get involved with others in a personal relationship when we are not on the same foundation. They will always tend to draw us away from Christ instead of us drawing them to Christ.