Tertullian believed that baptismal regeneration came into effect after the resurrection of Christ, but he acknowledged that justification was through faith alone prior to that time:
Well of course baptism wasn’t required before it existed! Regenerational baptism had no meaning until Christ.
Tertullian acknowledges that Abraham was saved through faith alone, but he dismisses Abraham as an exception to the rule. The apostle Paul, however, says that Abraham is the rule (Romans 4:13-16). Paul also denies that Christians are under a “law of baptizing” or any law of works (Romans 3:27, Galatians 3:21-25).
And yet Paul himself was baptized (cf. Acts 9:17-18), and he baptized Lydia and her household (cf. Acts 16:14-15), a jailor and his household (cf. Acts 16:27-34), Crispus and his household as well as many other Corinthians (cf. Acts 18:8), and disciples in Ephesus (cf. Acts 19:1-5).
In his letters, Paul speaks highly of baptism:
“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.” (Romans 6:3-4)
“For by one Spirit
we were all baptized into one body – Jews or Greeks, slaves or free – and all were made to drink of one Spirit.” (1 Corinthians 12:13)
“For as many of you as were
baptized into Christ have put on Christ.” (Galatians 3:27)
“There is one body and one Spirit, just as you were called to the one hope that belongs to your call,
one Lord, one faith, one baptism, one God and Father of us all, who is above all and through all and in all.” (Ephesians 4:4-6)
“In him also you were circumcised with a circumcision made without hands, by putting off the body of flesh in the circumcision of Christ; and you were buried with him in
baptism, in which you were also raised with him through faith in the working of God, who raised him from the dead.” (Colossians 2:11-12)
Where does he imply that this baptism is optional or that it is a “work”?
Tertullian goes on, later in his treatise, to add other works to the gospel. He says that people preparing for baptism should “pray with repeated prayers, fasts, and bendings of the knee, and vigils all the night through, and with the confession of all by gone sins” (20). hmmm??
How do you suppose a person should prepare for baptism? Even Peter told the crowds to repent and
then be baptized (cf. Acts 2:38).