William Reid's book, The Blood of Jesus, was published in 1866. This book focused upon the blood of Jesus for salvation, the forgiveness of sins, and true prayer. William Reid was absolutely confident that the Holy Spirit always bears witness to the blood of Jesus. True prayer is based upon the blood of Jesus.
William Reid wrote, "In all true prayer, great stress should be laid on the blood of Jesus. Perhaps, no evidence distinguishes a declension in the power and spirituality of prayer more strongly than an overlooking of this. Where the atoning blood is kept out of view, not recognized, not pleaded, not made the grand plea, there is a deficiency of power in prayer."
When we speak of the blood of Jesus, we always refer to his atoning sacrifice at the cross. The word blood speaks of a violent, sacrificial death. In the Old Testament, blood sacrifices were in the place of those who offered them. They pointed toward the one and only sacrifice that could take away our sins. True prayer is based upon the blood of Jesus (Hebrews 10:1-10).
The priests of the Old Testament prayed to God on the basis of a blood sacrifice. On the Day of Atonement, the High Priest sprinkled the blood on the mercy seat, praying for the people of Israel. He could not enter the Holy of Holies without the blood (Leviticus 16:11-14). New Testament believers have access to God in prayer through the shed blood of Jesus.
