Eph 4: One Baptism - but which one?

In the presentation of the 7 unities of the Spirit in Ephesians 4:3-7 we are instructed there is ONE baptism. But in Matthew 3:11 we are shown 3 different baptisms in one verse. Contradiction? Or does scripture clearly identify the ONE baptism that applies in the 21st century, during the Dispensation of the Grace of God (Eph 3:2)? Please have your KJV Bible at hand as you listen, as the answers MUST come from scripture. Search the scriptures daily, whether those things are so.