'Separating' in the Bible

So when Peter went up to Jerusalem, those of the circumcision [certain Jewish believers who followed the Law] took issue with him [for violating Jewish customs],

for before the coming of certain from James, with the nations he was eating, and when they came, he was withdrawing and separating himself, fearing those of the circumcision,

If therefore one shall have purified himself from these, in separating himself from them, he shall be a vessel to honour, sanctified, serviceable to the Master, prepared for every good work.

by this new and living way which He initiated and opened for us through the veil [as in the Holy of Holies], that is, through His flesh,