The way of Godliness consists of these two things: True (pious) doctrines and good works. Without good works, true faith is not acceptable to God, likewise, good works are not acceptable to Him in the absence of True Faith (pious dogma).
It is not always possible to fulfill the usual rules; one must take circumstances into account and try to fulfill what they make possible, as far as one can. The demons themselves are not unmindful of this law. So, being in constant enmity with us, they prevent us from doing what is possible and urge us to do what is impossible.
If you are a friend of Christ you should have as friends persons who are of benefit to you and contribute to your way of life. Let your friends be men of peace, spiritual brethren, holy fathers. It is of such that our Lord was speaking when He said: 'My mother and brethren are those who do the will of My Father who is in heaven.' (cf. Matt. 12:49-50).