"But evil men and impostors will proceed from bad to worse, deceiving and being deceived. You, however, continue in the things you have learned and become convinced of, knowing from whom you have learned them, and that from childhood you have known the sacred writings which are able to give you the wisdom that leads to salvation through faith which is in Christ Jesus." (2 Timothy 3:13-15)Paul contrasts two lives: those who continue in the truth of the gospel and those who continue in error. The Greek word translated here for "deceive" is the same word from which we get our word for "planets." In ancient days astronomers used to stare at the sky and noticed that all heavenly bodies cut regular arcs across the skies. All, that is, except for seven. They were call "Planets" or "wanderers" for they wandered from the right way of the other stars as they traveled the skies. The Planets were those who "erred" and left the "right" path for another. Similarly Paul contrasts those who continue to walk in the truth of God from those who seek after innovation or new ideas that lead them down a diverging path towards error.
Most often, those who end up in error, do not do so through great departures from truth. Most of the time it is the result of numerous tinny deviations from the truth experienced over great periods of time. A ship sailing across the ocean can make the smallest of errors in its navigation and end up completely missing its mark (which, by the way, is one definition of sin: to miss the mark). To be honest, none of us have perfect possession of the truth. However, if we refuse to allow the truth to correct us, to cause us to change our coarse, then we too, in time, will find ourselves in error. We must allow truth to refine our own truth least through stubbornness and pride we end up where we did not intend to go.
Paul encourages Timothy in two things that would help him stay true to the truth. First he was to remember from whom he learned the truth. Paul as his teacher had significance in that Paul was an apostle. The apostles were those who had been either personally disciple by Jesus or had been taught the gospel directly from Jesus. Paul was very clear about how he came to know the gospel. Like the other apostles, he learned it from Jesus. "For I would have you know, brethren, that the gospel which was preached by me is not according to man. For I neither received it from man, nor was I taught it, but I received it through a revelation of Jesus Christ." (Galatians 1:11-12) Furthermore, Timothy had the witness of the character of Paul testifying that those things which he preached were true for Timothy saw the reality of them shine forth in the life of Paul his teacher. We must give careful consideration to the memoirs and letters of the apostles as to those who personally received the message and the commission to teach it to us.
Secondly, Paul reminds Timothy of the scriptures he knew prior to being saved. The scriptures Paul is referring to are the Old Testament scriptures. Paul tells us that these scriptures can make us wise for salvation for they foreshadow and prophesy of the grace and forgiveness we have now received through Jesus Christ. We must not neglect the written history of God's interaction with mankind nor His revelations in days gone by. The Old Testament scriptures, as is true with all scriptures, all lead us to Jesus and the truth of His message which He came to reveal to us. By holding firm to the writings of old and the writings of the apostles we will ensure that we do not end up in error. By continuing in these things, we will find truth and the power of the truth to change our lives.