Possible meanings are 1) the Holy Spirit is the one who baptizes us, "For one Spirit baptized us" or 2) that the Spirit, like the water of baptism, is the medium through which we are baptized into the body, "For in one Spirit we were all baptized" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-metaphor]])
This can be stated in active form. Alternate translation: "God gave all of us the same Spirit, and we share the Spirit as people might share a drink" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-metaphor]])