This is sort of a combination of the two previous thoughts, and is arguably the crux of all of John's teaching. Jesus came to be with us, he saved us from sin and death, and he is sovereign. This is the song of the beloved disciple's life, resonating from him with every word and movement. It is what he has experienced firsthand, and it is affirmed by the Holy Spirit within every believer. We know this testimony to be true because of the Holy Spirit's confirmation.
So, the question arises. If this is built into us as believers, to know this truth in our very bones, how does it show up in our lives? Because it consumed John's life entirely! He understood the gravity of God's love and the power of Christ coming in the flesh. He knew sin well and felt the burden lifted mercifully by Jesus. And he saw Jesus hang on the tree and heard him whisper It is finished. It changed his life and took over his whole being; it was all that mattered to him because it is all that matters. So, when you looked at John (if these letters are any indication), you saw the love of Christ and the power of the Holy Spirit. You saw a man freed from the bonds of sin and rejoicing in that freedom. This was John, the son of thunder now the son of God, living fully in the new self. And so should it be with us as we grow in our relationship with the Lord. Less of us, and more of Him and His good work reflected in our lives. Our words, our actions, our decisions and priorities become His declaration of love and truth to a lost and dying world, to a suffering church, and to a weary soul.