J C Ryle
We learn from these verses that keeping Christ’s commandments is the best test of love to Him. This is a lesson of vast importance and it needs to be continually pressed on the attention of Christians. It is not talking about religion, and talking fluently and well, but steadily walking in Christ’s ways, that is proof that we are true believers. Good feelings and desires are useless if they are not accompanied by action. They may even become mischievous to the soul, induce hardness of conscience and do positive harm.
Passive impressions which do not lead to action gradually deaden and immobilise the heart. Living and doing are the only real evidence of grace. Where the Holy Spirit is, there will always be a holy life. A jealous watchfulness over tempers, words and deeds, a constant endeavour to live by the rule of the Sermon on the Mount, this is the best proof that we love Christ.
Of course such maxims as these must not be wrested and misunderstood. We are not to suppose for a moment that keeping Christ’s commandments can save us. Our best works are full of imperfection. When we have done all we can, we are feeble and unprofitable servants. “By grace are ye saved through faith . . . not of works” (Eph 2:8,9). But while we hold one class of truths, we must not forget another. Faith in the blood of Christ must always be attended by loving obedience to the will of Christ. What the Master has joined together, the disciple must not put asunder. Do we profess to love Christ? Then let us show it by our lives. The Apostle who said, “Thou knowest that I love Thee!” received the charge, “Feed My lambs” (John 21:17). That meant: Do something; be useful: follow My example.