There is nothing that men will not pervert. The very words of God, inscripturated for us, can be twisted, distorted and altered to give new meanings (2 Peter 3:16). They are the same words but with a totally new content. That is what makes heresy so insidious.
It is never even safe to trust that men are orthodox by the words that they use (God, Christ, sin, salvation, atonement, substitution, Trinity, justification, hell etc.). It is the meaning that those words are given that counts. God has joined names and things that belong together, heretics always separate them.
As Augustine says:
"We have, however, the catholic faith in the Creed, known to the faithful and committed to memory, contained in a form of expression as concise as has been rendered admissible by the circumstances of the case; the purpose of which [compilation] was, that individuals who are but beginners and sucklings among those who have been born again in Christ, and who have not yet been strengthened by most diligent and spiritual handling and understanding of the divine Scriptures, should be furnished with a summary, expressed in few words, of those matters of necessary belief which were subsequently to be explained to them in many words, as they made progress and rose to [the height of] divine doctrine, on the assured and steadfast basis of humility and charity.
It is underneath these few words, therefore, which are thus set in order in the Creed, that most heretics have endeavored to conceal their poisons; whom divine mercy has withstood, and still withstands, by the instrumentality of spiritual men, who have been counted worthy not only to accept and believe the catholic faith as expounded in those terms, but also thoroughly to understand and apprehend it by the enlightenment imparted by the Lord".
Augustine, A Treatise on Faith and the Creed, Chapter 1