One Lord, one faith, one baptism,

People's New Testament

4:5 One Lord. Christ, the Head of the church (1Co 1:13 Eph 1:10). All saints have one Master.

One faith. One Lord who is the object of faith, and whom both Jews and Gentiles lay hold upon by faith in him.

One baptism. All have been baptized into the one Lord upon the profession of the one faith by one rite. It would be utterly inconsistent with the Apostle's argument, if there could be anything divisive about baptism, as three different ways of administering itself. He is showing that there is unity in each one of seven essential features of Christianity, and hence all should seek to keep the unity of the Spirit in the bond of peace (Eph 4:3).

Wesley's Notes

4:5 One outward baptism.

Jamieson-Fausset-Brown Bible Commentary

5. Similarly "faith" and "baptism" (the sacramental seal of faith) are connected (Mr 16:16; Col 2:12). Compare 1Co 12:13, "Faith" is not here that which we believe, but the act of believing, the mean by which we apprehend the "one Lord." "Baptism" is specified, being the sacrament whereby we are incorporated into the "one body." Not the Lord's Supper, which is an act of matured communion on the part of those already incorporate, "a symbol of union, not of unity" [Ellicott]. In 1Co 10:17, where a breach of union was in question, it forms the rallying point [Alford]. There is not added, "One pope, one council, one form of government" [Cautions for Times]. The Church is one in unity of faith (Eph 4:5; Jude 3); unity of origination (Eph 2:19-21): unity of sacraments (Eph 4:5; 1Co 10:17; 12:13): unity of "hope" (Eph 4:4; Tit 1:2); unity of charity (Eph 4:3): unity (not uniformity) of discipline and government: for where there is no order, no ministry with Christ as the Head, there is no Church [Pearson, Exposition of the Creed, Article IX].

Matthew Henry's Concise Commentary

4:1-6 Nothing is pressed more earnestly in the Scriptures, than to walk as becomes those called to Christ's kingdom and glory. By lowliness, understand humility, which is opposed to pride. By meekness, that excellent disposition of soul, which makes men unwilling to provoke, and not easily to be provoked or offended. We find much in ourselves for which we can hardly forgive ourselves; therefore we must not be surprised if we find in others that which we think it hard to forgive. There is one Christ in whom all believers hope, and one heaven they are all hoping for; therefore they should be of one heart. They had all one faith, as to its object, Author, nature, and power. They all believed the same as to the great truths of religion; they had all been admitted into the church by one baptism, with water, in the name of the Father, and of the Son, and of the Holy Ghost, as the sign of regeneration. In all believers God the Father dwells, as in his holy temple, by his Spirit and special grace.