Paul's language is different than that of Jesus, but equally clear: "God be thanked that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you" Romans 6:17.
What does the apostle mean by this idea of obedience from the heart?
In his own context Paul's understanding is made evident: "Having been justified by faith we have peace with God through our Lord Jesus Christ, through whom we also have access by faith into this grace in which we stand, and rejoice in hope of the glory of God" Romans 5:1,2.
The gospel Paul proclaimed was the good news of justification by faith in Jesus Christ alone. He rejoiced in this amazing realization of divine grace. In verse 5 he explains the effect this gospel has on those who believe. "The love of God has been poured into our hearts by the Holy Spirit who was given to us." When the true gospel dawns upon the understanding, the love of God fills the heart with unquenchable desire to please such a wonderful Lord. It is with this gospel in mind that Paul speaks of believers obeying from the heart. He simply means obedience that has its origin in love, springing forth from a heart that has been won and transformed at the motive level.
The apostle John communicated the same idea when he said,"whoever believes that Jesus is the Christ is born of God and everyone who loves Him who begot also loves Him who is begotten of Him....This is the love of God, that we keep His commandments. And His commandments are not burdensome" 1 John 5: 1,3.
Love is the only source of true obedience, and true obedience is not a burden. In fact, it is the highest blessing the believer knows. The one whose religious experience centers in God's love can identify with David when he said, "I delight to do Thy will, O my God: yea, Thy law is within my heart" Psalm 40:8. Obedience that comes from the heart is obedience in which there is delight. It is not a pretended or disciplined delight that is put on for others to see. No, it is a personal delight, an inner joy that abides in the heart whether others are looking or not.
(Don't you want that kind of joy and delight. I do. May you be blessed as you read these pages, and if you have to read them over and over until it sinks in. It is such a joy to know that God puts the joy and delight in our hearts when obeying Him. Grandma Joan)