Updated: May 18, 2018
The example of Jesus, our Exemplar, was ever separate from “sin and sinners,” yet He dwelt among sinners, taught them to give up sin, ate with them, walked with them, and went to church with them on the Sabbath days.
Christ continued to attend church services—even though the scribes and the Pharisees were teaching false, man-made doctrines, even as some do in our day. But He always took a decided personal stand against error, and clearly declared Himself on the side of truth. While Christ was ever separated from their false teachings and sins, He still attended worship services with them and tried to give a positive witness for truth. So it should be with us.
https://www.andrews.edu/library/car/cardigital/Periodicals/Our_Firm_Foundation/2001/2001_12.pdf , Separation and Unity, Lloyd and Leola Rosenvold, page 23-24