The Feast Of All Saints

Kalendis Novembris solemnitas omnium sanctorum. Ecce, venerande pater Arne, habes designatam solemnitatem omnium sanctorum, sicut diximus. Quam continue in mente retineas et semper anniversario tempore colere non desistas; adtendens illud et intente considerans, quoniam, si Helias, unus ex illis in vetere testamento, oratione sua, dum voluit, claudere caelum potuit praevaricatoribus et aperire conversis, quanto magis omnes sancti in novo testamento? ubi eis specialiter et patenter claves regni caelestis commissae sunt, et claudere caelum possunt incredulis et aperire credentibus, si intima dilectione honorificantur a fidelibus et coluntur glorificatione eis condigna. Quod ut fieri digne possit a nobis, lumen verum, quod inluminat omnem hominem, Christus Iesus inluminet corda nostra, et pax Dei, quae exsuperat omnem sensum, per intercessionem omnium sanctorum eius, custodiat ea usque in diem aeternitatis. Hanc solemnitatem sanctissimam tribus diebus ieiunando, orando, missas canendo, et elimosinas dando pro invicem sincera devotione precedamus. Alcuinus, Epistola XCII,  Ad Arnonem Archiepiscopum Source: Migne PL 100 296a-b

The Kalends of November is the solemnity of All Saints. See, venerable father Arno, that you have a solemnity established for all the saints, as we have said. Keep it ever in mind and never cease to celebrate it on that date every year; attending to it and intently considering it, seeing that if Elijah, one of those of the Old Testament, with his prayer, as long as he wished, could shut heaven to sinners, and open it to the converted, 1 how much more can all the saints in the New Testament? For to them specially and manifestly have been entrusted the keys of the heavenly kingdom, and they can shut the heavens to unbelievers and open them to believers, if they are honoured with inward devotion by the faithful and are revered with the glorification appropriate to them. And that we may become worthy that this may be done appropriately by us, may the true light that illuminates every man, 2 Jesus Christ, illuminate our hearts, and may the peace of God, which exceeds all understanding, 3 through the intercession of all His saints, guard it until the last day. Let us precede this most holy solemnity by fasting for three days, praying, singing Masses, and giving alms for one another with sincere devotion. Alcuin of York, from Letter 92, To Arno The Archbishop 1 3 Kings 17 2 Jn 1.9 3 Phillip 4.7