In his book Spiritual Depression Martyn Lloyd-Jones deals with false teaching in the chapter "False Teachers." He points out that Christians can become miserable when they give in to following false teaching, much of which involves adding something extra to the gospel message. He spends some time emphasizing the fact that the truth as given by the apostles is what we are to follow; Scripture contains the apostolic teaching and that is what we are to regard as truth. Adding something to that constitutes false teaching. He uses the example found in Paul's letter to the Galatians, a group of people who were struggling over the question of whether or not a Christian had to be circumcised.In light of this risk of following a false teaching that adds something to truth (usually a work or an observance of some kind) Lloyd-Jones gives this piece of advice:
... always be careful to work out the implications of a teaching. This is what the apostle does in the second chapter of this Epistle to the Galatians. This new teaching appeared not to be denying the Christ at all, and yet the apostle is able to show very plainly that it denies Him at the most vital point. He even had to do that with the Apostle Peter at Antioch. Peter, who had been given a vision in connection with Cornelius (Acts 10) and had apparently seen these things very clearly, was influenced subsequently by the Jews and felt that he could not eat with the Gentiles but with Jews only. But Paul had to withstand him to the face and to tell him plainly that in doing this he was denying the faith. Now Peter did not want to do that, he did not want to deny his salvation by Christ through faith alone. But Peter had to be made to see his real position clearly and to understand that by his actions he was announcing that something in addition to faith in Christ is necessary. Let us then always work out the implications of what we say and do.
Christians are to be thinking people. I think we sometimes forget that. There is so much talk of our "experience" that we often don't sit down and think through something to see its logical conclusion. I know I don't do that often enough. I remember a couple of years ago, I was upset about a few bad choices that one of my children had made. My first reaction to this was that I had been a bad mother, that something I had done was the reason for the poor behaviour. My husband suggested that I think through the ramifications of that: if I took the blame for every bad thing my children do, does that mean I take the credit for everything good they do? Am I willing to rob God of the glory of His working in my children? It was a good point.
I remember when I was a new Christian and I wanted to feel "clean" as compared to the way I was before. I "added" a lot of unnecessary things to my faith, avoidance of certain activities. As I grew, I did slowly realize that my faith was not based on the avoidance of those things. But I was immature in my belief. Falling prey to false teachers, however, isn't limited to the unlearned, though. We can all give into that. The desire to add something to the gospel is a reflection of our natures, the belief that we can be good enough on our own.