Charles Spurgeon 
Prayer Meetings – Preparing fot the Week of Prayer [EPUB ebook] 

"All these continued in common agreement in prayer and supplication." Acts 1:14.
In all churches that are not fully bound and bound by liturgies and rituals, it has been common to hold meetings for social prayer.
We call them prayer meetings.
Now, it may be profitable, from time to time, to look at some of our institutions, see if they are scriptural to realize their defects, see in what sense they can be improved or observe their merits so that we can be further induced to carry them .
The subject of this message was suggested by the fact that we will meet for a day of prayer tomorrow, it is the prayer meetings assemblies of the people of God for worship of this peculiar kind that consists of each expressing his desire before the Lord. Let me share with you this message