This is a story of a question, "what is this Love?"  A man asks this question 3 times.  
The first time he asks it he is standing at the altar looking at his bride coming down the isle.  He sees her, his knees shake a bit & he wonders, "What is this love?"  
The second time he is in the delivery room holding his baby for the first time.  Unable to speak through joyous tears he asks, "what is this love?"  
The 3rd time he asks this question it is after replaying the loves of his life both wife and child, but this time in the context of watching a DVD of "the passion of the Christ".  Here realizes that is a story about a love as well. But this love is deeper still.  This love was sacrificial, A love from the Gospel. Realizing That God's love for him was strong enough to endure the cross,  he dusts off his bible, renews his faith & looking at the Gospel he is asking, "what is THIS love?"  ;)