John Chrysostom (attributed)

But the Lord so answers him, as at once to lay bare the dissimulation of his enquiry, Jesus saith unto him, Thou shalt love the Lord thy God with all thy heart, with all thy soul, and with all thy mind. Thou shalt love, not ‘fear,’ for to love is more than to fear; to fear belongs to slaves, to love to sons; fear is in compulsion, love in freedom. Whoso serves God in fear escapes punishment, but has not the reward of righteousness because he did well unwillingly through fear. God does not desire to be served servilely by men as a master, but to be loved as a father, for that He has given the spirit of adoption to men. But to love God with the whole heart, is to have the heart inclined to the love of no one thing more than of God. To love God again with the whole soul is to have the mind stayed upon the truth, and to be firm in the faith. For the love of the heart and the love of the soul are different. The first is in a sort carnal, that we should love God even with our flesh, which we cannot do unless we first depart from the love of the things of this world. The love of the heart is felt in the heart, but the love of the soul is not felt, but is perceived because it consists in a judgment of the soul. For he who believes that all good is in God, and that without Him is no good, he loves God with his whole soul. But to love God with the whole mind, is to have all the faculties open and unoccupied for Him. He only loves God with his whole mind, whose intellect ministers to God, whose wisdom is employed about God, whose thoughts travail in the things of God, and whose memory holds the things which are good.