Titus 1:10

For there are many unruly men, vain talkers and deceivers, specially they of the circumcision,

The persons in view here are not the hierarchical Jews of the secular state of Israel who also were vigorous opponents of Christianity, but the company of Jews who had indeed accepted Christ as the Messiah, having been baptized into the faith, and who, through inadequate understanding of Christianity, were attempting to bind the forms and ceremonies of Judaism upon Christians. This seems to have been especially true of that large group of Pharisees who had accepted Christ (Acts 15:5). Their teaching was totally wrong, and their motives were far from holy; because they evidently hoped to enlist Christians as keepers of Jewish rites out of regard to the fees that would be collected. They were unruly, insubordinate, vain, empty-headed deceivers, there being no grounds whatever upon which the true church could accommodate their behavior.