Christ refers to this when He says: “If a man love me, he will keep my words.” These words are those concerning His death and resurrection, not the word of Moses or the Ten Commandments. These ought also to be reverenced and obeyed, as God aforetime ordered it, but they contain not the consolation of the Gospel; they do not pacify the conscience, but rather increase the dread and fear of God’s displeasure; and this in proportion as we realize our weakness and transgressions. The Word of our Lord Jesus Christ, however, is the greatest and best gift. Christ says of those who possess this treasure and firmly hold to it under all circumstances, that the Father will love them.

It is a peculiarity of St. John, which is not so perceptible in the other Evangelists, to direct people first to Christ, and then through Him to the Father. And thus it must be, as Christ Himself says in our text. We must first know Jesus and love Him; we must have full confidence in His condescension and loving kindness. Where this love and confidence prevail, there there can be no doubt as to the love of the Father toward us. We will then disregard everything else that might disturb us, being assured that God is gracious to us through Christ. We will fear neither sin, the devil nor death, because God loves us, inasmuch as we love Christ. (Luther’s House Postil, Second Sermon for Pentecost, Volume 2, p. 600)

When such love is wanting, we cannot do the will of our Lord unceasingly, for He does not reward us with worldly honors and wealth, but with life everlasting. This is what Christ teaches us here. He tells us: My reward you will obtain in the life to come; therefore you must above all things have love towards me, for then you will adhere to my Word under all circumstances, even at the risk of your life. But if this love is lacking in your hearts you will not keep my Word, but will yield to danger, adversity and tribulation, which will finally plunge you into impatience and despair.

He who knows Christ in true faith and love will not be dismayed at these adversities, but will meet them boldly, convinced of the assistance of his Lord, and strong in the knowledge that He died, was buried, and arose again for us, and that therefore He cannot be opposed to our welfare. Thus love is intimately connected with faith and overcomes all danger and misfortune, without regarding the displeasure and wrath of the world. True love concerns itself about Christ and His Word, and pays no attention to the anger of the world. (Luther’s House Postil, Second Sermon for Pentecost, Volume 2, p. 599-600)

The word “love” is also used in this connection, because Christ foresaw with what great difficulties he would have to contend who would receive His Word and persevere in it. Manifold tribulations, which tend to arouse impatience and dissatisfaction, will present themselves. Besides these, the temptation is near at hand to think: I am myself to blame for what I endure; why did I preach and confess the Word publicly? If I had kept my peace and had exercised within myself only the faith in God’s Word and His gifts, no one would have molested me, and others, more competent than I, might have more successfully undertaken the task of a public confession and of teaching. Now I am in a great strait, for I am not only unsuccessful in my attempt, but am also in danger of losing my life for it. Such disquieting thoughts and temptations to despair cannot be overcome and banished from our hearts, nor can we immovably adhere to the Word, unless we have within us that love, of which Christ speaks in our text. Then every preacher, yea, every Christian, can exclaim: Let happen what will, I will nevertheless hold fast to the Word and will never deny my Lord and Saviour; for I enlisted in His cause for His glory, and not to please men, therefore I will endure all to the very end. (Luther’s House Postil, Second Sermon for Pentecost, Volume 2, p. 599)