The way of discipleship is a path of following Jesus through the influence of others who are following Jesus. Paul wrote,
“Follow my example as I follow the example of Christ” (1 Corinthians 11:1)
Some have said, “The Scriptures were incomplete, this as a stop gap measure.” Yet Jesus elevated example-
He appointed twelve that they might be with him and that he might send them out to preach (Mark 3:14)
Without teaching of the word we miss the principles, but the teacher will be watched to understand how it is lived. Paul writes-
Join together in following my example, brothers and sisters … (Philippians 3:17)
To the extent we follow the example of Christ we become an example worth following. We have little idea of how people see our lives and the impact this has on their walk with God. The verse goes on –
and just as you have us as a model, keep your eyes on those who live as we do.
We must take responsibility to choose how we are influenced and from whom we gain our perspective of what it looks like to follow Christ. It is good to be close enough to these examples to see their lives. The contrary message is also given-
… watch out for those who cause divisions and put obstacles in your way that are contrary to the teaching you have learned. Keep away from them. Romans 16:17
The measure of the ones we are to avoid is the fruit of their lives as much as their teaching.
adaringfaith 
Derek,
You may need to unpack your final sentence … “The measure of the ones we are to avoid is not doctrine, but the fruit of their lives”.
Can it really be either/or: don’t we need both?
Surely we need to test the doctrinal basis of those of whom we may be unsure, not simply judge them by their “fruit” which may be very deceptive and appear to be very “spiritual” yet not arise from a life grounded in Christ.
On the one hand we have Christ’s teaching “A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit” (Mat 7:18), but have to also remember John’s concerns regarding the deceptiveness of false teachers: “If anyone comes to you and does not bring this teaching, do not take them into your house or welcome them. Anyone who welcomes them shares in their wicked work” (2 John vs 10,11)
Blessings – Ian
Hi Ian, yes you are right. I was a bit surprised by the focus on fruit, but since the obstacles that they put in our way are contrary to the teaching we have learned there must clearly be a teaching element to what we are to look out for. So, thanks for the correction. God bless, Derek