"Your religion is what you do with your solitude"
Archbishop William Temple
Basically, when no one is around, just you and God, wherever your thoughts, desires and actions go to is what you REALLY believe. It is so easy for us as human beings to "say" something out of our mouth...to use our vocal chords to "dress" ourselves in a particular garment. But what our heart is truly wearing is shown eventually by our actions, not what we say. Most of the time, this comes out when no one else is watching, no one that would judge us or criticize us.
For me, the key is a constant realization that God is watching everything, is with me in everything. Scripture says that one day He WILL judge, He will ask me, "what did you do with your life in the solitude, Rowland?"
That's enough for me to at least work hard to be a person where integrity shines like the sun, even when no one else is there to enjoy the daylight!