If god wont decide for that for whom which person will be partner, then human wont get marry. God is the first person who decides and writes our fate. so due to that fate people get married on the earth. As god stay in heaven so Marriages made at heaven is the true statement
Of course this topic is metaphorical and must not be taken in literal sense (everyone knows marriages is a function in earth). Marriage is an important part of one's life, a turn in one's life where he starts a new family, new bonds and relationships so it is something very valuable and that's why marriage is of heaven. but in some cases (or many these days) it could also end up as hell!
Marriages are made on earth not in heaven or hell.Because it depend on the partner.If he is agood person it is like a heaven if he is abad person it is like a hell.
may be yes,may be no but one thing is for sure, to maintain it you need to work hard and marriage calls for constant awareness of happenings in your life and working hard on it.