In addition to having both husband and wife being believers in God - particularly the husband loving his wife as “Christ loved His church - I would also add making sure you LIKE each other as friends.
Many married couples I’ve been around say they love each other, but they don’t seem to like each other very much. I’m speaking from my own parent’s example. They are still married, but they don’t seem to enjoy each other’s company very much and are cross and rude to each other. They stayed married solely out of commitment - which I respect and appreciate - but it saddens me that I don’t believe they ever were friends.
Liking each other and becoming each other’s best friend is a big plus when it comes to happiness in marriage. My wife and I just celebrated our 36th anniversary and we enjoy each other’s company as much or,more than we ever did.
My advice to young people - know God, follow His commands regarding sexual purity, marital commitment, and loving/respecting each other - but make sure you LIKE each other before you ever get to the point of marriage.
One side note, I’ve heard many times from well meaning Christian advisors, and I am a Christian as well, that when the apostle Paul tells husbands to love their wives and wives to respect their husbands, somehow that means that wives don’t have to love their husbands and that husbands don’t have to respect their wives. I believe that is a distortion of what Paul was trying to say.
Paul was tying to say that real, Godly marital love is impossible without both husband and wife respecting and loving each the other. Does Christ only “love” His church, yet has no respect for it? Are we to only “respect Christ” and yet not love Him as well? Is genuine love possible without respect? I don’t think so.
I do think my parents love each other, but they really don’t have much respect for each other, so while they are still married, I don’t think they have much joy.