Why is family so difficult?

Why is it that we find it more difficult to talk to family about religious matters than we do a complete stranger or other friend? Now, don't get me wrong, my family are all born-again believers that are assured of their salvation and final destination; but, some of their attitudes toward people that they call friends that belong to another Christian faith that doesn't have enough right to be as assured of salvation alarms me, yet I can't find it within myself (even with God's conviction and help) to say anything. Do they care so little about where these people whom they refer to as "friends" will be going that they are unwilling to share with them the correct beliefs that will point them in the right direction so they can be together in heaven? Doesn't sound like much of a friend to me.

Lord, please give me the strength to say something before it's too late. Amen!