Acts 15:5

‘But there rose up certain of the sect of the Pharisees who believed, saying, “It is needful to circumcise them, and to charge them to keep the law of Moses.”

All were aware of why this deputation from the believers at Syrian Antioch had come. It was so that they might come to a decision, taking into account the authority of the Apostles and the position of the Jerusalem church, on the question as to what further was to be required of Gentiles who became Christians and were baptised.

So the circumcision party began by putting their case. They included among them Pharisees who had come to believe in Jesus Christ, but considered that the tenets of the Pharisees had to be maintained. They argued that all who responded to Christ and became Christians had necessarily to be circumcised so as to enter into the covenant, and must then observe the whole Law of Moses (and many would then have added - ‘according to the tenets of the Pharisees'). This would involve among other things Temple worship and the offering of sacrifices when in Jerusalem, the payment of the Temple tax, separation from Gentiles who did not observe the laws of cleanliness wherever they were, regular washings in order to maintain cleanliness, avoiding all that could render unclean according to Jewish principles, abstaining from the eating of blood and of various meats, strict observance of the Sabbath by not working, and a following of the multitude of Laws that governed the daily living of every Jew.