1 Corinthians 12:13

For in one Spirit were we all baptized into one body, whether Jews or Greeks, whether bond or free; and were all made to drink of one Spirit. [Paul here proves the unity of the church by the method of its creation. One Spirit, acting through the apostles and all other evangelists and ministers (1 Thessalonians 1:5), had begotten people of different races and nationalities and conditions (John 3:5), and had caused them to be baptized into the one church, and had bestowed itself upon them after they had been thus baptized (Acts 2:38). Thus it had made them one organism. Paul speaks of the bestowal of the Spirit under the figure of the living water used by Jesus (John 7:37). As the spirit of a man keeps up the organic unity of the body, so the Spirit of God had vivified and organized the church.]