The chief thing to be attended to is, that [family worship] may be a spiritual service; and the great evil to be dreaded and guarded against in the exercise of every duty that returns frequently upon us, is formality. If a stated course of [it] is kept up as constantly in its season as the striking of the clock, in time it may come to be almost as mechanically performed, unless we are continually looking to the Lord to keep our hearts alive.