2. Only people baptized in the Churches of Christ will be saved.

See here (https://www.christiancourier.com/articles/1176-the-truth-on-baptism-should-not-be-watered-down) and here for examples of this teaching.

If those who are not circumcised keep the law’s requirements, will they not be regarded as though they were circumcised? ²⁷The one who is not circumcised physically and yet obeys the law will condemn you who, even though you have the written code and circumcision, are a lawbreaker.²⁸A man is not a Jew if he is only one outwardly, nor is circumcision merely outward and physical. ²⁹No, a man is a Jew if he is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code. Such a man’s praise is not from men, but from God.” –Romans 2

RT – Pay particular attention to the assertion/accusation. Now go to the web link and see if the author of the article anywhere says what is asserted. In fact, the author of the article simply lays out a case for biblical baptism. There was nothing pejorative in what was written. Moreover, the passage referenced in Romans 2 by the author of this web-article lifted the passage out of the context in which Paul was addressing his words. Paul was talking about the Jew who was a hypocrite; that is, he insisted on obedience to the Law of Moses, but refused to adhere to it himself (note this especially in 2:17-29). Baptism and circumcision are not the same. Baptism applies to both the male and female; circumcision applied only to the male. Baptism applies to the males and females of all nations; circumcision applied only to the Hebrew (a descendant of Abraham). Baptism applies to people who have come to hear and understand the message of God with a penitent heart; circumcision applied only to the male who understood nothing, but experienced pain.