“I do not ask on behalf of these alone, but for those also who believe in Me through their word; that they may all be one; even as You, Father, are in Me and I in You, that they also may be in Us, so that the world may believe that You sent Me…” (John 17:20-23 NASB)
In verse 23, the Lord Jesus prays “…that they may be perfected in unity, so that the world may know that You sent Me…” Those who are unsaved will react to our message by what they hear us say and, more importantly, do. It is imperative that we show unity and love as Christians, if that is what we want to show others about Christ. If God is love and His children do not show or share that love, we cannot show an accurate picture of God to others. So if we want the world to know about God and His message of salvation, we need to be loving and unified as Christians to an unsaved world.
That our love for each other would result in people coming to know Christ.