Prayer is the main secret of success in spiritual business. It moves Him who can move heaven and earth. It brings down the promised aid of the Holy Spirit, without whom the finest sermons, the clearest teaching, and the most diligent labors, are all alike in vain. It is not always those who have the most eminent gifts who are most successful laborers for God. It is generally those who keep up closest communion with Christ and are most constant in prayer.