Where and when did the religion began?

Answer 1

It is hard to pinpoint exactly where and when the 'religion' began.

The beliefs of the Church start at the beginning of time - Creation. God created Adam and Eve and they certainly had a relationship with God. When the eating of the apple happened though (original sin) the relationship between humans and God changed. This needed to be corrected and that is why Jesus coming is so important - his death and resurrection saves us from sin and promises us eternal life. So that's the beginning or foundation of basic beliefs, but is this the beginning of the official religion.

As stated in the creed, the Catholic Church is apostolic which means there is a direct line from Jesus apostles to the people of the Church today - basically the apostles shared the Good News and appointed or ordained new 'leaders' to carry on the Church, who ordained more 'leaders' and so on through to the Pope, cardinals, bishops, priests etc who lead the Church today. So the Church could have started officially with the apostles,

However they used Jesus as the model for their work so really it started with Jesus.

The Feast of Pentecost is the Church's birthday. This is when the Holy Spirit came down upon the apostles and gave them the confidence and the guidance to continue Jesus mission. So the religion could have started officially at Pentecost.

The apostles carried on Jesus mission which he himself had begun in and around Jerusalem. So this again suggests that the Church or certainly the basic ideas of the Church started with Jesus.

In more modern times however, there have been a number of councils set up to discuss the catecism of the Catholic Church. So perhaps these councils, where the beliefs were discussed, debated and decided upon is the official founding of the religion.