For those of us who view our scouting program as part of our church's ministry, this can be a very tricky line to tread. This is true especially for those serving in a role like Chaplain in a multifaith Boy Scout Troop.
Within Scouting, generally speaking, we don't want to try to impose our specific religious beliefs on others. These scouts each come from families which have their own faith tradition. As a Scout Leader, It's not my role to give religious instruction to the scouts. If they have questions, I can answer them, but my main role in regards to faith is to set a good model for them to follow. As I've heard it stated before, "We should be able to set an example, so that people around us will know we are Christians, even if we don't tell them." But from a scouter's point of view, I want to encourage the scouts to follow their family's faith. This is Faith Modeling, where I can show the boys what someone who sincerely follows their faith looks like. That means I've got to be on my best behavior and set a good example for them at all times.
Faith Teaching is something quite different. This is what one might do as a Sunday School teacher, or at Vacation Bible School, or in some specifically religious setting. If you have done a good job reaching out to the scouts in your unit and inviting them, hopefully some of the youth from scouts will also be in the sunday school class. But at any rate, their presence there at this kind of event means that the parents have entrusted you and your congregation to lead the child in a religious education. Although it might be the same leader, and the same kid, and in some cases even in the same classroom in the church basement... It's two different settings.
It doesn't mean that you quit being a Christian when you put on your scouting uniform. But it does mean that you respect the differences in situation, and remember that some parents have entrusted you with imparting Scouting's Values, while other parents have entrusted you with imparting specific religious beliefs. Although there is a HUGE overlap between the two, there is a distinction, and that's the difference between Modeling your faith and Teaching your faith.