Typically, this person would be what I would call a 'cultural Christian'. One who attends service on a Sunday, but ignores his Lord for the rest of the week. He does not show the fruits of his Christian service, but lives as one of the world during the week.
I often do this and often when I am an impatient and intolerant driver on the roads.
Most important I feel, is a quiet time of devotions each and every morning. This sets the tone for the day and gets us soaking in His Spirit