Love The Lord Your God With All Your Heart.
Jesus said to him, You shall love the Lord your God with all your heart, with all your soul, and with all your mind. Matthew 22:37 NKJV
All the law is fulfilled in one word, and that is, love. See Romans 13:10. All obedience begins in the affections, and nothing in religion is done right, that is not done there first. Love is the leading affection, which gives law, and gives ground, to the rest and therefore that, as the main fort, is to be first secured and garrisoned for God. Man is a creature cut out for love thus therefore is the law written in the heart, that it is a law of love. Love is a short and sweet word and, if that be the fulfilling of the law, surely the yoke of the command is very easy. Love is the rest and satisfaction of the soul if we walk in this good old way, we shall find rest.
The love of God is the first and great commandment of all, and the summary of all the commands of the first table. The proper act of love being complacency, good is the proper object of it. Now God, being good infinitely, originally, and eternally, is to be loved in the first place, and nothing loved beside him, but what is loved for him. Love is the first and great thing that God demands from us, and therefore the first and great thing that we should devote to him.
Now here we are directed, To love God as ours Thou shalt love the Lord they God as thine. The first commandment is, Thou shalt have no other God which implies that we must have him for our God, and that will engage our love to him. Those that made the sun and moon their gods, loved them, Jeremiah 8:2; Judges 18:24. To love God as ours is to love him because he is ours, our Creator, Owner, and Ruler, and to conduct ourselves to him as ours, with obedience to him, and dependence on him. We must love God as reconciled to us, and made ours by covenant that is the foundation of this, Thy God.
To love him with all our heart, and soul, and mind. Some make these to signify one and the same thing, to love him with all our powers others distinguish them the heart, soul, and mind, are the will, affections, and understanding or the vital, sensitive, and intellectual faculties. Our love of God must be a sincere love, and not in word and tongue only, as theirs is who say they love him, but their hearts are not with him. It must be a strong love, we must love him in the most intense degree as we must praise him, so we must love him, with all that is within us, Psalm 103:1. It must be a singular and superlative love, we must love him more than any thing else this way the stream of our affections must entirely run. The heart must be united to love God, in opposition to a divided heart. All our love is too little to bestow upon him, and therefore all the powers of the soul must be engaged for him, and carried out toward him. This is the first and great commandment for obedience to this is the spring of obedience to all the rest which is then only acceptable, when it flows from love. - Matthew Henry