'Counterfeit' in the Bible

But [like a boxer] I strictly discipline my body and make it my slave, so that, after I have preached [the gospel] to others, I myself will not somehow be disqualified [as unfit for service].

Just as Jannes and Jambres [the court magicians of Egypt] opposed Moses, so these men also oppose the truth, men of depraved mind, unqualified and worthless [as teachers] in regard to the faith.