Do you know that faith is gift from God? It is, so do not be afraid to talk to anyone because God has given us each a measure of faith. Read this:
Rom 12:3
3 For by the grace given me I say to every one of you: Do not think of yourself more highly than you ought, but rather think of yourself with sober judgment, in accordance with the measure of faith God has given you.
NIV
Now what that measure IS and IF they agree with you is between them and God you just need to try to teach them.