Good post via Jeremy Olson:

The first Great Commandment: "You shall love the Lord your God with all your heart, and with all your soul, and with all your mind"

The second Great Commandment: "You shall love your neighbor as yourself"

Doesn't it seem weird to anyone else that Jesus was only asked by the lawyer what the greatest commandment is, not the two greatest? Here's my guess as to why he gave two answers. Jesus knew that one who loved God would naturally serve others because the two ideas are intricately linked so much that it is impossible to do one without also doing the other. The second is the fruit of the first. If someone is not doing the second, I would argue (and it would seem that Jesus is hinting at it), that the first is not being done either. Trying to do the first without doing the second is void of meaning...