Colossians 3:15, I would say, gives a basic of how to live in unity with others who are God's children >
"And let the peace of God rule in your hearts, to which also you were called in one body; and be thankful." (Colossians 3:15)
Whoever obeys God in this peace is already in unity . . . "in one body" with all the others who are submissive to God in His own peace. And the scriptures can feed us plenty about how to get here, and how to stay here > not only by doctrinal agreement, but by how God changes us to be and to live and to love . . . like Jesus in us, sharing this with us (Galatians 2:20).
But one basic of this is how our Heavenly Father in us personally guides each of us, in His own peace; He guides us according to all He knows is really happening all around us, and all He knows is really going on in other people. And what He does with each of us is in coordination with all the others who are obeying Him in the whole body of Jesus.
How God is coordinating the body of Jesus is at a higher level of ability and intelligence, than how He coordinates a physical human body; because this peace is spiritual with God's own level of harmony, being shared with us. This unified coordination is already happening in His peace in whoever is obeying Him in His peace.
So, yes there are decoy things to get our attention away from personally submitting to God in His own peace which has us now in this unity.
There are people who are not going to ever obey how God has us in unity. They will do other things, and maybe call attention to what they dictate we have to do. If ones are calling people to what is not God's way, of course it never will work, because >
"God resists the proud" (in James 4:6 and also in 1 Peter 5:5).
"If anyone desires to come after Me, let him deny himself, and take up his cross daily, and follow Me." (in Luke 9:23)
"And walk in love, as Christ also has loved us and given Himself for us, an offering and a sacrifice to God for a sweet-smelling aroma." (Ephesians 5:2)
This way of loving has us in unity with Jesus and therefore with one another. All scripture can somehow help us to find out how to love, and how to personally submit to our Heavenly Father in His own peace which has us sharing as His family while reaching with hope for any and all others > love "hopes all things" (in 1 Corinthians 13:7)
But in case someone's efforts for unity are elsewhere . . . big mistake!!
Also, we now can join one another, in prayer >
"Therefore I exhort first of all that supplications, prayers, intercessions, and giving of thanks be made for all men, for kings and all who are in authority, that we may lead a quiet and peaceable life in all godliness and reverence. For this is good and acceptable in the sight of God our Savior, who desires all men to be saved and to come to the knowledge of the truth." (1 Timothy 2:1-4)
Jesus on the cross died with hope for any and all people. Love "hopes all things" (in 1 Corinthians 13:7). So, as we pray with this hope for any and all people, we thrive in unity with Jesus and strengthen our unity with one another, in this loving.
So, our true unity is deeper than outward conformity of groups and individuals. Jesus says do not evaluate by appearances > John 7:24 > how people can make things look will be no guarantee of real unity!
