Successful marriages have two qualities in common even though the marriages themselves are as diverse as the couples in them: acceptance and faith.
The honeymoon ends when the spouse in question (always the other spouse) does something thoroughly inexplicable and totally at odds with the logic of the judging spouse. Something that (try as they sincerely might) they cannot put themselves in that somebody else’s shoes and come up with any justification for what they did. At this point they simply say, “I don’t understand what s/he did, but who says I have to understand everything to live with it?” It was at Sinai that the Jews agreed to a relationship regardless of how much they agreed with G‑d. “How could G‑d…” does not have to be a prelude to ending a relationship: it can be a deepening of a relationship. “You may not be a perfect G‑d in my mind, but you’re still mine. So now if I’m not so perfect, I’m still Yours.” … After so many years, and so many disappointments, and things we simply can’t understand, we still love this marriage and love this G‑d of ours and His Torah.

Maybe we don’t say I love you often enough, maybe we don’t say I’m sorry, maybe we forget a thank you, but we never forget each other.

from: www.chabad.org/library/article_cdo/aid/384525/jewish/What-Makes-a-Marriage-Tick.htm