Quote Originally Posted by Philipvs Vallindervs Calicvla View Post
God gave an ordinance to Peter to baptise the gentiles in Acts 10. Baptims replaced circumcision as the mark of the covenant. 300 years later the Council of Nicea determined that baptism with water in the name of God the Father, Son and Holy Ghost was necessary in order to enter into full comunion with the Church; they also determined that the act was effective even if the baptising priest was an Arian heretic.

Irrc the Sunday thing came in around 200 AD when Christians began celebrating the Resurrection rather than the Sabbath.
The baptism of Cornelius seems to be tied in with the rest of the chapter, where it is revealed to Peter that all things are clean etc. In giving Cornelius the Jewish custom of baptism, he was emphasising his point that Gentiles were no longer considered unclean and unfit to take part in Jewish ceremonies (see verse 28). Also, in verses 37-8, Peter actually refers to water baptism as the baptism that John preached, and distinct from the one preached by Jesus. It is not part of the Gospel and it can't be, otherwise the prisoner on the cross could not be saved.

The verse also doesn't support the idea that baptism is the new circumcision. When Peter says he is to baptise them, he also notes that this is because they had received the Holy Spirit. Obviously this supports the idea of baptism if anything being an expression of faith, not a sacrament, and questions the practice of infant baptism.