Love God, and
Love your neighbor as yourself.
Given that our neighbors are made in His image, I wouldn’t put the “love your neighbor” very far into the distance. Besides, the relationship with your fellow man is where the rubber hits the road. The hard part of maintaining your relationship with the Creator is playing nicely with His other children.
I actually believe the bible is about only two things: Man’s relationship with God and man’s relationship with his fellow man, who is made in God’s image.