Those interested in eternal salvation must be of Christ. He is the only one through whom redemption comes (1 Pet. 1:18-19; Jn. 3:16). It is through Him alone that one may go to the Father (Jn. 14:6). So, what is required to be of Christ?
In dealing with problems at Corinth, Paul said, “Now I say this, that each of you says, ‘I am of Paul,’ or ‘I am of Apollos,’ or ‘I am of Cephas,’ or ‘I am of Christ.’ Is Christ divided? Was Paul crucified for you? Or were you baptized in the name of Paul?” (1 Cor. 1:12-13).
To be of Paul, he had to be crucified for you and you must be baptized in his name. So, to be of Christ, He must be crucified for you and you must be baptized in His name.
The former is done. Jesus gave His life for the sins of all men (Jn. 1:29; Heb. 2:9). The latter is up to each one of us. All who are baptized in the name of Christ are His (Acts 2:38). If you are not baptized in the name of Christ, you are not of Christ—you are lost.