This document discusses the importance of prayer and provides guidance on how to pray effectively. It makes the following key points: 1) Prayer is the most important subject in practical religion and a habit of prayer is a sure mark of a true Christian. 2) It provides guidance for both those who do not pray, urging them to start, and those who do pray, encouraging them to make prayer regular, earnest, and full of faith. 3) When praying, believers should be humble, specific in their requests, intercede for others, thankful, and watchful over the influences on their prayers. Frequent and fervent prayer is necessary for spiritual growth.