Reading John 8:12-41, do you think Jesus in verses 31-32 is referring to what he has just said to the Jews as ‘his teaching’ or do this passage refer to his teaching more generally? The distinction is important as the first interpretation says it is our core belief in understanding who Jesus really is that is the truth that sets us free. The second interpretation (as taught in the ICC) is that once a person does the things Jesus does, then they know the truth and are set free. The context is vital here.
A general rule of biblical interpretation is that the obvious interpretation is almost always the correct one, unless there is a strong reason to believe otherwise. I think this applies to John 8:31-32. Jesus is saying to his hearers that if they hold to his teachings, they will know the truth and by doing so they will be set free from their sins. The Greek word translated "hold to" here is meno which means remain, stay, dwell. This seems to imply that this is not just an acknowledgement of his teaching, but rather an acceptance of and obedience to his words. Jesus did not say "If you hold to this teaching" (ie. what he just taught). He said "If you hold to my teaching." This certainly seems to be a general statement. If one chooses the less obvious (in my opinion) interpretation that Jesus is only referring to the specific things which he has just taught, then what did he just teach? It is not even clear that John 8:31 follows immediately John 8:30. In other words, for all we know this passage may not even be from the same public speech as that which preceeds it.
Let us assume for a moment that John 8:31-32 does follow immediately after 8:30. If it does, then Jesus is talking about the fact that what he teaches is "just what the Father has taught me." In that case, he is talking about his teaching in general anyway. For this reason, I just do not see that big a distinction in how to apply this passage.
I do NOT believe that this passage is saying if a person does what Jesus does then they will know the truth. I am part of the ICC, and I have never heard this passage taught exactly that way. I have heard it taught that Jesus is telling us that if we hold to his teaching–in other words if we accept what he says to be true and put it into practice, then we will know and understand the truth, and therefore we will be set free. So, I do not know what you have been taught, but I have never heard that it is in doing what Jesus did that we know the truth, but it is in obeying what he taught. I also do NOT think that this passage can mean simply if we believe in who Jesus is we will know the truth and be set free. The Greek word implies a lot more than simple belief/acknowledgement, but it implies living his words.
I hope this is clear.