Great question! Baptism is a physical representation of what should happen in the spiritual realm. Baptism represents the death, burial and resurrection of our Lord and savior Jesus Christ. (1st Corinthians 15:13) In the book of John 3:1-21, Jesus told Nicodemus "You must be born again." We cant enter in through the flesh, because no flesh shall glory in His presence; Nor can we please God in our flesh. Because God is Holy, He said "be ye Holy for I am Holy" and our flesh is corruptible. Therefore, baptism is essential to our overall transformation as we convert from carnal(flesh) to celestial(spiritual). As we begin to receive the word of God in our spirit we begin to be convicted. When we are convicted there is a disturbance within our spirit that desires to be right and do right also known as surrendering. We will always fail trying to do God, know God and receive God through our own knowledge and intellect.(Note: Peters revelation did not come until He renewed his mind; Then God revealed to him who Jesus was. Therefore we must die to our sin, and allow the spirit of God "His Word" to penatrate our hearts, wash us and make us whole. We show this through baptism. We illustrate dying to our sin nature which is our past ways, and former lifestyle and being Renewed in mind, body and the Spirit. (Romans 12:1-2). So regarding the oxymoron about Grandma dying before being saved; Only God knows that His Word broke up the fallow grounds of her heart and she received salvation which is Jesus Christ. (Believe,Have Faith,Confess Jesus is Lord, Repent & Be Transformed.)