Every Lord's Day, people across our nation and throughout the world gather for the purpose of worshiping God. The fact that they gather in places which are designated for worship and the fact that they gather together at a specific time which has been set apart for the activity of worship, does not necessarily mean that they actually worship God.
Worship is an activity which is both external as well as internal.
The word's of Christ emphasize the vital importance of the internal aspect. When we speak of internal worship, we are speaking primarily of the condition and the activity of the inner man or what we might call the heart. It is possible to go through the motions of worship without engaging the heart. Such worship is not acceptable to God. This can be illustrated by showing the importance of obedience being from the heart.