I want to comment on what you said:
'Many marriages begin wonderfully, but over time from past feelings there is no trace. For the marriage to last happily ever after, the couple needs to listen to the advice God gives them.'
That is why I will teach that non-christians do not understand love that the Bible says that marriage should be based on.
I will say that when most people think that they are in 'love' and should get married because of that love, then they are proably confusing love with lust.