Objective standards

It seems standard fare in Protestant America for the average citizen to choose the standard by which they form their thoughts and actions.  One example of this is the manner in which people raise their children.  Mr and Mrs X, self identified Christians, raise their children according to a set of standards that they believe are in accordance with the Christian faith.  But Mr and Mrs Y, also self professed Christians, observe particular thinking and practices in Mr and Mrs X's children that they believe to be sinful.  Who is right? Or is there even a set criteria by which these different standards can be judged?
And even consider the position into which this puts the child.  If this is a particularly introspective child, he may wonder which path to follow.  From a Protestant perspective, I honestly cannot identify an answer.  But from the historic Orthodox perspective, there is an answer.  Because the Protestant world has no final authority to which to appeal, they must appeal to private interpretation.  But the Orthodox world can and does appeal to the historic faith. As Orthodox, we say that the faith and practice of the church as it has been held and practiced for the last two thousand years is our final appeal.  That which the apostles practiced and taught, that which the church has always practiced and believes, based on the faith of the apostles, is that standard we hold.
We must learn to submit to the authority of the apostolic faith, regardless of how it makes us feel.