Respect
Respect each other on all points, whether it's the way they raise their kids or the food they choose to eat.

Shared Faith
If there is shared faith, the relationship has strong roots that will last through death. Jesus gave us the gift of choice - choosing to believe in and be saved by Him. He also asks us to love everyone, whether or not they have been saved. A friendly relationship is not doomed to failure by lack of shared faith, it simply won't have that deep bond. Romantic relationships, however, depend on that bond to be full and complete.