In the name of the Father and of the Son and of the Holy Spirit. Amen.
1. The chief sin of humanity is unbelief. This fact is attested throughout the Scriptures. In Genesis chapter 3, humanity’s fall into sin occurred because of unbelief in God’s Word: “Did God actually say…” (Genesis 3:1). So, seeing that the tree was good for food, delightful to the eyes, and that it offered the promise of wisdom, Eve trusted the serpent’s word and in so doing disbelieved God’s goodness and so took of its fruit and ate. And in this act of eating, the world was plunged back into the formless void and darkness of un-creation through humanity’s sin. Later in the Scriptures, we are told of how this darkness fell upon God’s people, Israel, in the fall of the Northern Kingdom, which was a result of their sin of unbelief. The Scripture says of Israel’s exile: “And this occurred because the people of Israel had sinned against the LORD their God . . . they would not listen, but were stubborn, as their fathers had been, who did not believe in the LORD their God” (2 Kings 17:7, 14). So, exile and darkness was Israel’s fate. In Romans 1, Saint Paul speaks of God’s wrath against those who traded faith in Him for worshipping and serving the creation rather than its creator (Romans 1:25). “For although they knew God, they did not honor Him as God or give thanks to Him, but they became futile in their thinking, and their foolish hearts were darkened” (Romans 1:21). In today’s Gospel text, our Lord makes clear that the persecution of God’s people occurs “because they have not known the Father, nor Me” (John 16:3). And finally, just a few verses after today’s Gospel text, our Lord speaks of sin as unbelief, which the Holy Spirit must confront through His chief works of convicting “the world concerning sin and righteousness and judgment” (John 16:8). And our Lord tells us that the Spirit’s work to convict of sin is “because they do not believe in Me” (John 16:9). The chief sin of humanity is the darkness of unbelief. And the sin of unbelief is not relegated to pagans alone. All sin of humanity is at its core unbelief. This is true, even for Christians.
2. Each and every time that you sin against the Lord, it is an act of unbelief. That is not to say you cease believing in the Lord Jesus altogether, but you do act in unbelief. When you gossip and slander others, you demonstrate an unbelief in God, becoming willfully darkened to the truth that He is the Father of all, that He has made all men, not just you, in His image. Gossip is an act of unbelief because it demonstrates that you are the center of your world and are acting as your own god. When you commit the sin of gluttony, you demonstrate an unbelief in God, taking the good gift of food that He has given you and elevating it to a place of importance far beyond God’s good intentions. Food becomes your comfort, your companion, and your pleasure rather than God, and so you act in the darkness of unbelief. So, too, with the sin of impatience—when you commit the sin of impatience, you demonstrate an unbelief in God—thinking and acting as if the world centers around you and that your priorities are of utmost importance, and so you act in unbelief. When you covet that which you have not been given by God, you demonstrate an unbelief in His provision and His goodness, that He can and will provide you with the light and life needed to support this body and life. In doubting this, you act in unbelief. When you commit the sin of laziness, you demonstrate an unbelief in what God has said about you and the vocational responsibilities He has granted you. Selfishly desiring rest without work and pleasure without sacrifice, you willfully live and act in the darkness of unbelief. My friends, Your chief sin is unbelief, therefore you need our God to bring you out of that darkness into the light of His truth.
3. Today’s Gospel text sits beautifully between our Lord Jesus’ Ascension and the coming of the Holy Spirit at Pentecost to show us how our Triune God brings us from the darkness of unbelief into the light of His truth. Christ promises that the Helper, or Paraclete, will come to lead Christ’s people into the light of truth: “But when the Helper comes, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father, He will bear witness about Me” (John 15:26). Before we can consider the coming of the Holy Spirit, we must consider Christ’s sending of this Spirit. How does the holy God come to dwell within sinful man but through the person and work of Christ Jesus, our Lord? Christ’s sending of the Holy Spirit is not akin to a baseball manager sending in the closer. The Lord Jesus is not going to the dugout in sending the Holy Spirit. Our Lord’s life and ministry has come to its crescendo at the cross, the empty tomb, and the Mount of Ascension. And the coming of the Holy Spirit does not bring this crescendo to a close. Our Lord Christ remains at work after His ascension by sending His Spirit to dwell in us so that we might live even now in His life and light: “In Him was life, and the life was the light of men. The light shines in the darkness, and the darkness has not overcome it” (John 1:4-6). In fact, the light has overcome the darkness in our Lord Jesus. Our Lord Jesus entered the darkness of our sinful world on a lonely night in Bethlehem. And for us men and for our salvation, He went to the cross as the darkness of sin and death both literally and figuratively surrounded Him. He took your sin of unbelief upon Himself, allowing Himself to suffer the abandonment of the Father which you deserve, as He cried out, “My God, My God, why have You forsaken Me?” (Mark 15:34). The Father forsook the Son for your sake. Our Lord Jesus surrendered His life to the darkness of death so that your unbelief might be atoned for upon the cross. And now that you have been brought out of the darkness of sin, the light of the Spirit of Truth is yours.
4. My friends, the Christian life is a constant inner struggle between the darkness of the old man and the light of the Holy Spirit. But rest assured in this, that though we wait seven days to celebrate the coming of the Holy Spirit on Pentecost, even now He has come to you. In fact, He is coming to you right now through the very words of this humble sermon. “When the Helper comes…He will bear witness about Me” (John 15:26), says the Lord Jesus. Though you cannot see Him, the Spirit of Truth is bearing witness of the Lord Jesus through these words. Though you sin much, the Holy Spirit never ceases to declare to you the truth of salvation. Though your sins of unbelief leave you in darkness, Christ has died and Christ has risen that the light of life might be yours. He has ascended to the right hand of the Father so that He might sprinkle clean water on you and make you clean from all your uncleanness (Ezekiel 36:25). From all your unbelief, He cleanses you. And through the work of His Holy Spirit, Christ places a new heart and a new spirit within you (Ezekiel 36:26) to sanctify you and to grant you the promise of dwelling in the eternal Promised Land (Ezekiel 36:28).
5. The Spirit who proceeds from the Father is sent to you by the Son so that, having heard the testimony concerning the Lord Jesus, you might be brought out of the darkness of unbelief into the light of God’s truth. And it is a comfort that this is the work of the Holy Spirit, not merely the work of humans. And so, the fact that our Lord teaches here that the Spirit proceeds from the Father is not a throwaway line. The Spirit’s procession from the Father is crucial to the comfort we find in this article of faith. The Holy Spirit proceeds from the Father in that His source is the one substance which He receives from the Father. While a unique person from the Father, the Spirit and the Father share the substance of their being and the eternal love which the Holy Trinity has for humanity. The Spirit has His source in the Father in a parallel manner to how the Son is eternally begotten of the Father. All three persons of the Holy Trinity are of the same substance and will and love. And so, the Nicene Creed’s confession that the Holy Spirit proceeds from the Father and the Son is not opposed to the teaching of John 15. In fact, our Lord’s teaching here confirms this Nicene faith. The one who sends the Spirit does so because His one substance with the Spirit allows Him to do so. Now, if this deep theology is a bit over your head, then believe this simple truth. The Holy Spirit is Christ’s Spirit, and both share the same fervent desire that you dwell for eternity in the light of Christ. So, Because the Holy Spirit’s work to bring us out of darkness and into the light of truth is the work of God Himself, you can be assured that He does and will succeed in accomplishing this for you. The Lord Jesus has sent the Holy Spirit from the Father to bring you out of your unbelief into the light of His truth. Of this, there can be no doubt, because “If God is for us, who can be against us?” (Romans 8:31b).
In Jesus’ name. Amen.