In every area of life I can think of, conditions are necessary. Contracts almost always contain clauses, caveats, and quid pro quos. Jesus even provided conditions for the marriage "contract," allowing one whose mate commits fornication to divorce and remarry an eligible person (Mat. 19:9) or one whose mate dies to marry an eligible person (Rom. 7:1-4). Though making no allowance for remarriage, as some say, Paul does add that one does not have choose marital obligations to a mate over Christ (1 Cor. 7:15). Further, one is not required to remain in a situation where abuse and physical danger is a viable threat either to that one or whatever children are involved, even if such reprehensible conduct does not allow the victim the right of remarriage (cf. Mat. 5:32; 19:9). Love does not act unbecomingly (1 Cor. 13:5), and those who are lazy, lustful, selfish, demeaning, wrathful, and the like may bear the fruit of disdain and distance from a fed-up or heart-broken spouse.
That said, there is an alarming amount of "conditional love" that defies sympathy. Through the years, I have known those before and after marriage who made the physical weight and appearance of their loved one a condition of their love. For others, it was money or salary. For others still, it was social status and social-climbing. Perhaps, with some brainstorming, we could grow this list of "provisos" much longer. This approach to "love" that says "I will love you if…," "I will love you when…," "I will love you unless…," or "I will love you until" runs contrary to the spirit of Christ. He is the standard of love. Husbands are to love their wives like Christ loved the church (Eph. 5:25). Wives are to be taught to demonstrate selfless love to their husbands, too (Ti. 2:4).
Consider Christ's love. He loved us when we were helpless, sinful enemies (Rom. 5:6-10). He loved us before we loved Him (1 Jn. 4:19). He continues to love us, though we fall short (Rom. 3:23; 8:38-39). That does not mean that He will unconditionally save us, but the Bible's clear indication is that He will continue to love us no matter what. Certainly, that will revolutionize our thinking as a Christian, but we should allow it to revolutionize our earthly relationships. As John says, "Beloved, if God so loved us, we also ought to love one another" (1 Jn. 4:11).