What we need in the Christian life is to get believers to want to do God’s will, as much as other people want to do their own will. And this is the idea of the Gospel. It is what God intended for us; and it is what He has promised. In describing the new covenant in Heb. 8:6-13, He says it shall no more be the old covenant made on Sinai, that is, a law given from the outside, controlling a man by force, but it shall be a law written within constraining a man by love. “I will put my laws,” He says, “in their mind, and write them in their hearts.” This can mean nothing but that we shall love His law, for anything written on our hearts we must love. And putting it into our minds is surely the same as God working in us to “will and to do of His good pleasure,” and means that we shall will what God wills, and shall obey His sweet commands, not because it is our duty to do so, but because we ourselves want to do what He wants us to do. Nothing could possibly be conceived more effectual than this. How often have we thought when dealing with our children, “Oh, if I could only get inside of them and make them want to do just what I want, how easy it would be to manage them then!” And how often practically in experience we have found that, to deal with cross-grained people, we must carefully avoid suggesting our wishes to them, but must in some way induce them to suggest them themselves, sure that then there will be no opposition to contend with. And we, who are by nature a stiff-necked people, always rebel more or less against a law from outside of us, while we joyfully embrace the same law springing up within.
God’s plan for us therefore is to get possession of the inside of a man, to take the control and management of his will, and to work it for him; and then obedience is easy and a delight, and service becomes perfect freedom, until the Christian is forced to exclaim, “This happy service! Who could dream earth had such liberty?” The Christian’s Secret of a Happy Life.