Our new pastor is spearheading a 40-hours devotion in our pastorate, we've never done one of these before. What does the ideal 40-hours devotion look like and how can the laity make it the most spiritually beneficial and explain it to people who may not be used to things adoration and meditative prayer.
What's the purpose of a 40 hours devotion?
The 40 Hours Devotion comes from the 40 hours that Christ’s body traditionally remained in the tomb. 40 is a significant number in the Bible, often tied to trials and/or suffering: the Israelites wandered in the desert for 40 years, and Christ was tempted in the desert for 40 days prior to the start of his ministry.
However the most important thing about them forty hour devotion is to honour Jesus in the Blessed Sacrament. Other secondary purposes may exist.
But the evidence in all these cases only goes to show that the practice was then being introduced of exposing the Blessed Sacrament with solemnity on occasions of great public calamity or peril, and that for such expositions the period of forty hours was generally selected. In past centuries, especially in the late Middle Ages, the devotion was practiced during times of crisis. Bishops frequently ordered exposition of the Sacrament for "serious and general need." The faithful would come in shifts before the Sacrament seeking God's intercession during events threatening the local community, such as war, epidemics, drought or famine. Later it became common to hold the devotion around the feast of Corpus Christi.
One of the most important documents pertaining to this devotion is the Constitution Graves et diuturnae of Pope Clement VIII, of 25 November 1592, in which the pontiff strongly commended the practice of unwearied prayer.
<We have determined to establish publicly in this Mother City of Rome (in hac alma Urbe) an uninterrupted course of prayer in such wise that in the different churches (he specifies the various categories), on appointed days, there be observed the pious and salutary devotion of the Forty Hours, with such an arrangement of churches and times that, at every hour of the day and night, the whole year round, the incense of prayer shall ascend without intermission before the face of the Lord.
As in the case of a previously brief of Paul III, the keynote of this document is anxiety for the peace of Christendom. In 1731 Pope Clement XII issued a very minute code of instructions for the proper carrying out of the Quarant'Ore devotion, which is known as the "Instructio Clementina". - Forty Hours' Devotion
The 40 hour devotion in honour of the 40 hours Christ traditionally lay in the tomb may be very close to reality.
St. Charles Borromeo speaks as if this practice of praying for forty hours was of very ancient date; and he distinctly refers it to the forty hours our Lord's Body remained in the tomb, seeing that this was a period of watching, suspense, and ardent prayer on the part of all His disciples. - Forty Hours' Devotion