That verse refers to unbelievers, not disagreements between believers. Everyone claims they are the ones who have the true understanding of the word of God, but most contradict each other, so that's the point of this discussion, to find the truth.
If you think you know the truth, all that you can do is put your truth out there among the falsehoods. It is not we that will convict but the Holy Spirit. According to Isaiah 63: 9-10, the Holy Spirit is the "angel of His presence" . In other words where His Holy Spirit is, the Father is. It is through His Holy Spirit (Glory) that the Father interacts with our reality. Our reality is in the mind of the Father. That is why the Father is everywhere, knows everything, can do anything, and even transcends time. Christ is the image of the invisible God because Christ is filled with the Father's Spirit (Glory) through which the Father communicates His will and empowers Him to create our reality. When Christ went back to Heaven to get glorified, He was given His own glory to baptize people with so that He, as well as the Father, can be present in their being.
John 17: 20-23 Neither pray I for these alone, but for them also who shall believe on me through their word; That they all may be one, as thou, Father, art in me, and I in thee, that they also may be one in us; that the world may believe that thou hast sent me. And the Glory (Holy Spirit) which thou gavest me I have given them, that they may be one, even as we are one. I in them, and thou in me, that they may be made perfect in one;
Just as Christ is the temple of the Father and lives to do the Father's will, we become temples of the Father and Son and live to do the Son's will, which is also the Father's will. We get perfected when our motivation for every thought and action is love for God first, and everyone else as we love ourselves (as Christ commanded).