Ephesians 4:5 mentions Lord, faith and baptism, but it does not mean that there is only one Lord, only one faith or only one baptism. It is about believers or followers of Christ. Yet there is a lot of teaching going around, for example that there is only one baptism (i.e. water baptism). The word ONE in Eph4:5 refers to ONE AND THE SAME, meaning that ALL followers of Christ have the SAME LORD, SAME FAITH AND SAME BAPTISM. This is particularly important because the Bible cannot contradict itself for it says You cannot serve God and Mammon, meaning the Mammon is also a lord to some. In life we also know that golf, an illicit lover, one's job, etc, can also be our lords.
Humans, including Christians also have more than one faith. Faith that driving above the speed limit would not result in a ticket, faith that not studying would not fail them an exam, faith that is they give God will repay a hundredfold. And on baptism, the Bible is so abundantly clear (e.g. in Acts19:1-6 that there are many baptisms, and the Bible also mentions Baptism of the Holy Spirit, Baptism in the name of Jesus, Baptism into Jesus' death amongst others). So Eph4:5 is not saying there is only one baptism but that We all have the same, one baptism.
It was not asked what this one baptism in common is, that distinguishes a follower of Christ from other people, so I won't take up space here except to let us read what Paul said to the Ephesians in Acts 19:3 "...Unto what they were ye baptized?" Paul could not have asked that question if there is only one baptism. And verse 5 says "When they heard this they were baptized in the name of the Lord Jesus." Mind you, these Ephesians were apostles who had had John's baptism. Then in verse 6 "And when Paul had laid his hands upon them, the Holy Ghost came upon them; and the spake with tongues and prophesied." Simply put, three baptisms were mentioned in this passage, and one of them refers to the baptism which saves.
K C Toh