God bless you and greetings in the name of Jesus Christ who confronted error when he faced it (John 8:12-28).
The second step down was that they erred concerning the truth. They spoke contrary to the truth. The next three steps all concern themselves with the truth. Unless we relate properly with the truth, we are doomed to depart from the faith.
II Timothy 2:17-18:
And their word will eat as doth a canker [gangrene]: of whom is Hymenaeus and Philetus; 18 Who concerning the truth have erred, saying that the resurrection is past already; and overthrow the faith of some.
The resurrection had not passed. Paul had taught them better, but they questioned the integrity of God’s Word and spoke contrary to it. Remember the goal of the seducing spirits and doctrines of devils is to cause some to depart from the faith (II Timothy 4:1). That’s why it said it ate like a gangrene. It’s infectious; it will spread quickly through a fellowship.
Paul made disciples in Asia and separated them when others refused to believe. Again, Paul uses concrete examples of Hymenaeus and Philetus to make his point. Using their names indicates that they were more conspicuous members of a class of false teachers. We have to protect ourselves and our people from wrong doctrine; it’s harmful. If you listen to their ilk, you’ll get infected. . . the gangrene will spread. We discipline ourselves to stay put on the truth we have heard. Jesus warned his disciples that they had to continue in the Word.
Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed; 32 And ye shall know the truth, and the truth shall make you free.
It’s only when we continue in the Word that we maintain our freedom. It’s only the truth that can make us free, and it’s only continuing in the truth that will keep us free. We have to hold it fast. It’s important like Hebrews 2:1 says to not let it slip away. We have to give the more earnest heed to the things we have heard. We can’t afford to lose them.
The word “erred” in II Timothy 2 18 is the Greek word astocheō. It is only used three times all in the epistles to Timothy. It is translated “swerved” in I Timothy 1:6, and “erred” in I Timothy 6:21. It’s a compound word. It comes from “a,” a negative particle and “stoichos” meaning “an aim.” It is related to the word stoicheō. Stoicheō means walk, but it is not the typical word for “walk.” Peripateō is the more common word. It occurs 96 times, like in Ephesians 5:2, where it says “walk in love.” However, stoicheō only occurs 5 times. It means to “walk in a line, to proceed under another’s direction.”1 It carries a more orderly connotation according to a detailed standard, as in carrying out orders or following directions. It was sometimes used to describe soldiers who marched in response to the directions of their commanding officer. With the negative particle in front of it, astocheō means to swerve off target, to miss the mark, to not walk in an orderly fashion, to not carry out the standard or proceed as directed. They didn’t walk properly. They spoke against the truth. They overthrew the faith of some. The gospel becomes perverted, corrupt, and erroneous, under pretense of improving it. There seems to always be weak brethren ready to be deceived and misled by the deception.
 J. I. Packer, Keeping In Step With the Spirit (Old Tappan, N. J.: Fleming H. Revell Co., 1984), p. 11.