There is no material reason why we should worship at all, therefore our instinct to worship indicates a recognition of a spiritual reality, which is behind and in and above the physical reality. In other words, worship is based upon an intuition of the spiritual. This intution is overwhelming, fearful, and attractive all at once. It is a vision of god. Whether it be the puzzled upward glance of the primitive or the delighted love of the saint, it derives from a vision of god.
Atheists regard worship as a human fantasy.
An atheist would say you have no reason to be here on a sabbath morning. Worship is a total waste of time. But to a believer, worship is the most profound human response to reality. Worship points us towards the Reality of God. Worship gives, expresses, and maintains that which is the essence of all religion, namely a theocentric basis to life.