He loves her and he knows that she loves him as much. But, he's not sure whether the marriage will work or not.
According to him, he is not an easy going person, neither his future wife. They have been dating for almost three years, and engaged for five months now. They fought a lot.
So, I asked him, "Why did you decide to marry her at the first place?"
He answered, "Because I love her!"
"Then, that would be enough for the two of you. You will make it."
"What makes you so sure about it?"
"You both have been surviving these three years. Why should you worry about the years ahead? Learn from history, Sir!"