My mom saw a therapist after she divorced her third husband. I never met Dr T, but he gave her some great insight, and one thing she passed on to me was his idea of consonances --
You should be consonant in morality. You may not agree on the morality of everything, but you have enough overlap to find much common ground.
You should be consonant in interests. Not everything your lover likes will interest you, nor yours him or her, but you should have enough overlap that you can spend quality time together without resentment
You should be consonant in your spirituality. You need not agree on your view of faith (or its lack -- though he ever mentioned that, it seems apt here), but you shouldn't be hurt by your lover having a different perspective.
You should be consonant on your willingness to be parents. If one wants children and the other doesn't, that's a big warning sign.
You should be roughly consonant financially. If one partner brings in much more than the other, the temptation to power can undermine the relationship.
You should be consonant in morality. You may not agree on the morality of everything, but you have enough overlap to find much common ground.
You should be consonant in interests. Not everything your lover likes will interest you, nor yours him or her, but you should have enough overlap that you can spend quality time together without resentment
You should be consonant in your spirituality. You need not agree on your view of faith (or its lack -- though he ever mentioned that, it seems apt here), but you shouldn't be hurt by your lover having a different perspective.
You should be consonant on your willingness to be parents. If one wants children and the other doesn't, that's a big warning sign.
You should be roughly consonant financially. If one partner brings in much more than the other, the temptation to power can undermine the relationship.