Who Do We Unify With? (Ephesians 4:4-6)

Paul has just finished telling us to “put up with” each other’s differences for the sake of Gospel unity. However, just who are we supposed to cooperate with? Where is the line drawn?
One Body
There is only One Church, the Body of Christ. Christ has never been divided into Baptist, Presbyterian, Lutheran, etc. We are to forbear with and strive for unity among all true Christians.
One Spirit
All Christians have the indwelling Holy Spirit. How can the Holy Spirit in me reject the Holy Spirit in you? Notice, that in all of this Paul is not calling us to look at labels but the individual. Not all Baptists have the indwelling of the Spirit; therefore, those individuals are not our brothers. Not all Methodists have the indwelling of the Spirit; therefore, those individuals are not part of the body of Christ.
One Hope
Essentially there is only one destination for believers, eternity with Jesus Christ; this is the hope of our calling. If I am going to spend eternity with someone I need to learn to get along with them in this life.
One Lord
Lord is a title that essentially means “master” or “ruler.” It denotes sovereign control. Paul is here saying that all Christians have submitted themselves to the rule of Jesus Christ. Who is my brother or sister that I must tolerate and put up with? The one who has submitted themselves to Jesus. Again, this goes against all labels. Many professing Christians from every denomination have refused to submit to the Lordship of Jesus Christ; by the same token, many people from every denomination have submitted their lives to Christ. Who do we cooperate with? It is not the person with the label; it is the person with the life of submission to Jesus that we are to forbear with.
One Faith
There is only one true Gospel, but there are many heresies in the world. God has not called me to keep unity with every heretic who claims to be a Christian. No, I am only to maintain unity and cooperation with those who hold to the doctrine of Jesus Christ.
One Baptism
There is only one true baptism: total immersion, after conversion, in the name of the Father, Son, and Holy Spirit as a sign of our death to self and regeneration by Christ. Any other entrance into the church is contrary to Scripture.
One God
Many “Christians” believe in a false idol they call God or Jesus. However, this is not the One True God because their understanding of Who He is is contrary to Who He has revealed Himself to be. We are not to unify with heretical idolaters.
Application:
We must recalibrate our thinking away from the neat categories we have created. Our cooperation must be on a individual basis to see who is actually a regenerate follower of Christ. All believers have an obligation to not only keep the faith pure but keep the faith unified. We must follow Matthew 18 to either see heretics and sinners restored to the One True Faith or we must excommunicate them as unbelievers. All those within the faith we must unify with.