It is always interesting to track down the origin of certain rituals that are practiced under the name “Christian” which do not have their foundation in scripture. One specific ritual worth considering is the Roman Catholic practice of last rites.
To find out why this practice began, we have to go back to Tertillian who was a theologian who lived during the second and third century A.D. Tertillian was a materialist. He was not the kind of materialist we think of today, but the kind of materialist who believes that even spirit is material. This includes God Himself; though spirit was clearly a higher more refined type of material.
This played heavily into his views on baptism. Tertillian believed that the more refined spirit matter could bond quite well with the lower types of matter such as water. When a person was baptized, the Holy Spirit would bond with the water and somehow wash the person who was being baptized clean of sin. Thus making baptism part of regeneration.
Tertillian also believed that children should not be baptized. This is why many Baptists like to point to him to support credo-baptism, but the reason he thought children should not be baptized had nothing to do with Baptist beliefs as they are held today. Tertillian believed that once you were baptized, you would no longer be given grace if you sinned. If you did sin willingly, you would loose your salvation. At that point, you would have no further chance of redemption. Thus, you should not baptize children because they are certainly going to sin as they grow up. Tertillian, therefore, suggested that a person wait until they were about 30 years old before being baptized.
During this time, many people in the church were influenced by Tertillian’s beliefs, but they also realized that people would still sin after the age of 30. To protect people from sinning and losing their salvation, many church leaders began performing deathbed baptisms. This is why Constantine was not baptized until the end of his life.
Needless to say, those who held this view eventually began reject some of these ideas in order to return to a more Biblical understanding of baptism. However, the Latin Church never let go of the desire to perform a ritual at the deathbed to absolve someone from their sins. This is where the practice of last rites was born. It all stems from Tertillian’s aberrant theology regarding baptism, and, like Tertillian’s view of baptism, the last rites are still performed with the belief that they can offer a final purification of sin.
To give credit where credit is due, much of this information was gleaned from a Church history lecture by Dr. Gerald Bray from Beeson Seminary.