And the second is like, namely this, You shall love your neighbor as yourself. There is no other commandment greater than these.
All Commentaries on Mark 12:31 Go To Mark 12
John Chrysostom
AD 407
Christ looks for nothing else from you, in fact, Scripture says, than loving him with all your heart and carrying out his commands. I mean, obviously the person who loves him in the way he ought to love is also ready to carry out his commands. You see, when one is kindly disposed to another, he takes pains to do everything able to attract the loved one to love for him. So, we too, if we sincerely love the Lord, will manage to discharge his commands and do nothing capable of angering our loved one. This is the kingdom of heaven; this, the enjoyment of goods; this, blessings beyond number, being found worthy to love him sincerely and in the manner he deserves. Our love for him will be genuine if we give evidence of great love for our fellow servants as well as for him. Homilies on Genesis, Homily