CCC 1227 According to the Apostle Paul, the believer enters through Baptism into communion with Christ’s death, is buried with him, and rises with him:
Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, so that as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.1
The baptized have “put on Christ.”2 Through the Holy Spirit, Baptism is a bath that purifies, justifies, and sanctifies.3

1 Rom 6:3-4; cf. Col 2:12.
2 Gal 3:27.
3 CE 1 Cor 6:11; 12:13.