The following is taken from the book Preaching and Preachers. I love the book and think you should think about this quote:
I would put my exhortation to these listeners at its very lowest by telling them that if they have no other reason for being present at every service of the Church, that they should at any rate realise that there is great value in numbers.
Look at it like this. Think of a man who is not a Christian, a man of the world who suddenly finds himself in great trouble. He has a terrible problem and no one seems able to help him, Walking along the streets aimlessly he happens to pass a church, a place of worship, and he decides to go in wondering whether he will find help there.
Now if he finds just a little handful of people there, people who look miserable and, as the preacher begins to preach, keep looking at their watches repeatedly, he will come to the conclusion that there is nothing in it. He will conclude that this handful of people do this sort of thing probably because they were brought up to do so, and have not thought sufficiently about it even to stop doing it.
It obviously does not mean much to them; they are doing it clearly as a matter of routine or tradition, or out of a sense of duty. The poor man will be entirely put off; it will not help him at all.
But if he goes into a church which is packed with people and becomes conscious of a spirit of anticipation, and sees a people who are eagerly looking forward to something, he will say, ‘There is something in this. What is it that brings these people here, this great crowd of people?’
So he is interested immediately and begins to pay close attention to everything. The very fact of a crowd of people doing this has often been used by the Spirit of God to lead people to conviction and conversion. I have known this happen many times.
The trouble is that so many do not stop to think about these matters. They just go to the service as a matter of duty, and having done so feel better because they have done their duty. That attitude to a service obviously expresses itself and visitors sense this and draw the conclusion that there is not much value in it if this is the attitude of the regular attenders.
But, conversely, when they enter a place of worship where people attend because they feel that God meets them there, this also will transmit itself to them in some strange way that one does not quite understand. So they will feel that something real is happening, and it may well be used of God to bring them to a knowledge of the truth.
Martyn Lloyd Jones, Preaching and Preachers