I. The Apostle speaks first of one Lord. Those words would have at once recalled to a Jew the sentence which had been repeated to him since he could speak: "The Lord thy God is one Lord." And surely much of the emphasis of this Divine sentence lay in the word "thy." Multitudes of things surround thee and crave thy worship; there is One near thee, ruling thee, caring for thee, jealous of thee, who claims thy heart for Himself: He is the Lord.
II. "One faith." The Jew had been taught to put his whole trust in the Lord God of Israel. Faith or trust was the principle of his being; losing that, he lost everything. The different objects of sense were appealing to him every moment. He could care for them or dread them, but he could not trust them. He must have one faith, or they become his masters; he must have one faith, or there was nothing to bind him to his brother-Israelites; he must have one faith, or his manliness forsook him.
III. "One baptism." The baptism of John had been a witness that the one God of their fathers was calling them to turn round to Him from all the visible objects and the secret lusts to which they had yielded; that He was pardoning away their sins and confirming His covenant with them.
IV. "One God and Father of all." One Lord the law and the prophets had spoken of. But this name of Father, who had uttered that? It came forth when Jesus went up into the mount to proclaim the fulfilment, not the destruction, of that which had been said in the old time. Then did the belief of "one God and Father of all" begin to break through the Jewish exclusiveness, to prove that the Jewish election had this for its final result. One God and Father of all, because one Man who can say, "I came from the Father, and am come into the world; again I leave the world, and go to the Father."
F. D. Maurice, Sermons,vol. vi., p. 111.
References: Ephesians 4:7. Clergyman's Magazine,vol. ii., p. 98. Ephesians 4:7-12. Spurgeon, Sermons,vol. xvii., No. 982.