Alfred N. Gilbert preaches about the necessity of a radical and vital change in man, known as the 'new birth,' to be considered a true Christian. This change, symbolized as a 'new birth,' encompasses the entire nature of man - intellectual, emotional, volitional, and physical - and inducts one into the kingdom of God. The sermon delves into the specific aspects of man's nature that are transformed through this 'new birth,' highlighting the importance of belief, love, repentance, and obedience to Jesus Christ. The completion of this 'new birth' is signified by the act of baptism, representing the surrender of the physical nature to the commands of Jesus Christ.