Is baptism essential to salvation?

“He that believeth and is baptized shall be saved” (Mark xvi, 16).

“Except a man be born of the water and of the Spirit, he cannot enter the Kingdom of God” (John iii, 5).

“Go ye, therefore, and teach all nations, baptizing them” (Matthew xxviii, 19).

Was the penitent thief baptized?

Paul says: “I thank God that I baptized none of you, but Crispus and Gaius.... For Christ sent me not to baptize, but to preach the gospel” (1 Corinthians i, 14, 17).