Sadly I think that many people fall in love, or rather think they are in love, and make the step to get married. After a short amount of time they realize it was just lust, or something else that placed them in this situation.
Though marriage course before you get married are offered, they won't help if you feel at that point you are madly in love. Perhaps a test of love would be a better option. Some sort of trial where you have to stand beside your mate through hell, and if you still feel the same way, then you know you are in love.