Christianity began as a movement within the Jewish Faith. Jesus was a Jew, all the disciples were Jews, all the apostles were Jews, and almost all the miracles Jesus did were to Jewish people, with just a few exceptions
But some of the Jewish believers preached to those who weren’t Jews, and surprise, those people were giving their lives to Christ and experiencing a great revival.
Then came the controversy.
The Bible, in Acts 15, tells of a group of believing Pharisees telling people, especially the non-Jewish converts, they had to get circumcised or they wouldn’t go to heaven. After all, the Bible commands circumcision; so they weren’t obeying the Scriptures if they didn’t get circumcised, and you can’t go to heaven if you disobey the Bible.
It’s a bigger controversy than just circumcision, the Bible is full of laws that don’t address faith and daily living; the worship on Saturday, the Sabbath for instance; and Tithing, and not eating Pork, Shrimp, or catfish.
The Jewish Apostles in Jerusalem had to figure this out!
Their conclusion was, since God saved non-Jewish people before they were circumcised, they didn’t have to get circumcised to be saved and go to Heaven.
This, by the way, is a strong indication salvation is NOT a guess, people can know for sure they are saved or not. They knew by the movement of the Holy Spirit and a “know so” faith in Christ.
So they sent a letter abroad to the new non-Jewish believers with a list of requirements, and it is a short list:
“be responsible only for these bare necessities: Be careful not to get involved in activities connected with idols; avoid serving food offensive to Jewish Christians (blood, for instance); and guard the morality of sex and marriage. These guidelines are sufficient to keep relations congenial between us. And God be with you!”
Acts 1:29 (Message Bible)
What about circumcision? Not on the list.
What about Saturday worship? Not on the list.
What about Tithing? Not on the list.
What about eating catfish, shrimp, pork, or a whole host of other things? Not on the list.
Faith and salvation is about receiving the living Jesus Christ who paid for our sins with his own self-sacrifice. Full surrender to him, what the bible calls letting him live in you and you living in him is the source of life here and on the other side of eternity.
God’s object lessons can be strange. In the Old Testament, when God’s people complained poisonous snakes slithered out and bit them.1 God’s cure was to take an image of one of those snakes, put it on a pole and look at it! Those who looked lived and those who refused to look died. 
Patrikin - Kinship through The Father 