Balance and discernment

We have all heard the phrase, " The grass is greener on the other side of the fence," and we know what it means. But we also know the wisdom of avoiding or fleeing a bad or dangerous situation.  So how does one balance between these two?
Here is what I am getting at.  The Orthodox faith puts a great emphasis upon personal holiness and sanctification.  Almost at any cost, we are to take on ascetic endeavors appropriate to our specific situation.  We must learn to understand how to balance a life of holiness in the situation we live.  At what time and at what cost do we flee from an extremely ungodly culture?  Are we willing to give up comfort and ease, for holiness?