Lex orandi, lex credendi, lex vivendi

I read A Slice of Infinity yesterday and I just can't stop thinking about this statement:

There is a phrase in Latin that summarizes the idea that the way our minds and souls are oriented is the way our lives are oriented. Lex orandi, lex credendi, lex vivendi is an axiom of ancient Christianity, meaning: the rule of worship is the rule of belief is the rule of life. That is, the way we are oriented in worship (whatever it might be that we focus on most devotedly) orients the way we believe and, in turn, the way we live.*
*emphasis mine

Sola Deo Gloria!