Ephesians 4:4-6 There is one body and one Spirit—just as you were called to the one hope that belongs to your call— one Lord, one faith, one baptism, one God and Father of all, who is over all and through all and in all.
The Apostle Paul makes it a point to speak an awful lot about unity within the Church throughout his letter to the Ephesians. His efforts should not be overlooked. It’s obvious that unity is very important.
Many Christians think that they can live out the life of a Christ-follower apart from belonging to a church family, but in reality things were never designed to work that way. There is one body – and a body can’t fully function without all of its members. It was designed that way. There is one Spirit. We’re each indwelled by the Holy Spirit, but it’s not just for the purpose of solo living.
John Calvin once stated boldly that “those who separate themselves from their fellow believers estrange themselves from the kingdom of God.” He also said, “if we are not one body and one spirit, we are not fit for that inheritance.” This is strong wording, but it truly captures the nature of Paul’s letter and why he’s so adamant about talking to these people about unity. There is not Christianity, no Church, apart from that unity. Embrace your fellow Christians, flaws and all, because they’re your spiritual siblings and you need them as much as they need you.