I would suggest the answer is time. Infatuation is what we all feel from time to time when someone catches our eye, makes our heart race, but it passes eventually. But to pass the test of time, earn each others trust and respect, that takes time - and that is what true love is. You will soon see if you are lucky enough to be blessed with it.
Its hard to differentiate between the two since infatuation can sometimes lead to real love However, If you love some one you do not feel insecure there is trust in the relationship. When you are in love you work through problems. If you are infatuated you avoid them. An infatuated person would only focus on the physical aspect of the his or her partner while a person who is in love would emphasize more on their partners personality. A person in love will continue to love the other person as time ticks away in fact the love deepens as time goes by, while a person who is infatuated their feelings for his/her partner would begin to fade as time passes by. To sum it all up Love is when you love a person for who they really are. While Infatuation is being in love with the idea of love not the other person.