## But ##

Luke contrasts those who believe "salvation is only in Jesus" to some men from the Pharisees who believed in Jesus yet believe "circumcision is required for salvation."

## to circumcise them and to command them ##

"them" refers to non-Jewish believers who were not previously circumcised.

## to keep the law ##

"to obey the law" or "to follow the law"

## to consider this matter ##

"to discuss the difference in beliefs". That is, to debate the different salvation messages between Paul's gospel (salvation in Jesus) and the Pharisee's gospel (salvation in circumcision and law).