In his excellent work on a holy life, Gospel Conversation, Jeremiah Burroughs writes,

There are some who make profession of religion indeed, and, if you come to them before other company, their conversation seems to be very fair and square.  But just follow them to their families and see what they do there.  Will you see their conversation to be holy as becomes the gospel of Jesus Christ?

– Burroughs, Gospel Conversation: Conduct Worthy of the Gospel, 23.