Mark 16:16 & Luke 7:29-30
The debate over the necessity of baptism for salvation has raged for centuries. The bottom line seems to be, though, that baptism is according to the simple reading and understanding of the Scriptures absolutely essential to our eternal salvation.
The Lord himself said, "He who has believed and has been baptized shall be saved; but he who has disbelieved shall be damned" (Mk. 16:16). To many, this verse is clear and very much to the point if we believe and have been baptized, we will be saved. Yet, it has been argued by faithless men and women that one can be saved by believing only, that baptism is a mere sign of an inward feeling. Such is not only unscriptural, it is an open attack upon the authority of Christ given to him by God. Too, it is a demonstration of a heart that does not believe in God's omniscience or in his ability to communicate accurately his will to his creation (2 Pet. 1:3).
According to the gospel of Luke, "And when all the people and the tax gatherers heard (Jesus' preaching), they acknowledged God's justice, having been baptized with the baptism of John. But the Pharisees and the lawyers rejected God's purpose for themselves, not having been baptized by John" (Lk. 7:29-30). How did the people and the tax-gatherers acknowledge God's justice? By being baptized according to John's baptism. And being baptized according to the baptism of John. I believe Luke 7:29-30 is parallel in application to Mark 16:16.
For "he who has believed and has been baptized shall be saved; but he who has disbelieved shall be damned."
Guardian of Truth XXXVIII: 17, p. 4