Which is greater, love or fear of G-d? We are told if we do a mitzvah merely because we are afraid of the punishment that will come if we do not do it, then we would be serving Hashem from a lower level. But we are also told that fear of Hashem is the highest service. How can these two apparently contradicting statements be reconciled?
There are two levels of love and there are two levels of fear. There is lower level love and there is higher level love. Lower level love says, "I love you. I want you. Come to me." Higher level love says, "I love you. What can I do for you?"
Lower level fear says, "Okay, okay I will do whatever you want so you will not punish me." This is the fearful service that is lower than serving with love.
But there is also higher level fear. Higher level fear is more properly called Awe. There are two levels of awe of Hashem. The lower awe comes when the Jew reaches up towards Heaven. The higher awe comes when Heaven reaches down to the Jew… when Hashem shows the Jew some of His holiness. This awe of Hashem is the highest possible service. It is also the most loving experience possible because awe is filled with love.