Matthew Poole and continuators on Ephesians 4:3

3 Endeavouring to keep the unity of the Spirit in the bond, of peace .

Either unity of mind, or Spiritual unity as being wrought by the Spirit, and then he means that unity he spoke of, ch. 2.14, 15, 16. and 3.6. whereby the mystical Body of Christ.

i. e. In peace as the bond which keeps the Members or parts of the Church together, which by Dissentions are dissipated and scattered. The first step to this unity is Humility, for where that is not, there will be no meekness, nor forbearance, without which Unity cannot be maintained.