Since man’s life on earth is a time of trial, and all who would live devotedly in Christ must undergo persecution, and the devil your foe is on the prowl like a roaring lion looking for prey to devour, you must use every care to clothe yourselves in God’s armor so that you may be ready to withstand the enemy’s ambush.
Your loins are to be girt with chastity, your breast fortified by holy meditations, for, as Scripture has it, holy meditation will save you. Put on holiness as your breastplate, and it will enable you to love the Lord your God with all your heart and soul and strength, and your neighbor as yourself. Faith must be your shield on all occasions, and with it you will be able to quench all the flaming missiles of the wicked one: there can be no pleasing God without faith; [and the victory lies in this—your faith]. On your head set the helmet of salvation, and so be sure of deliverance by our only Savior, who sets his own free from their sins. The sword of the spirit, the word of God, must abound in your mouths and hearts. Let all you do have the Lord’s word for accompaniment.
Quia vero tentatio est vita hominis Super terram, et omnes qui pie volunt vivere in Christo persecutionem patiuntur, adversarius quoque vester, diabolus, tamquam leo rugiens circuit quaerens quem devoret, omni solicitudine studeatis indui armatura Dei, ut possitis stare adversus insidias inimici.
Accingendi sunt lumbi cingulo castitatis; muniendum est pectus cogitationibus sanctis, scriptum est enim: Cogitatio sancta servabit te. Induenda est lorica iustitiae ut Dominum Deum vestrum ex toto corde et ex tota anima et ex tota virtute diligatis, et proximum vestrum tamquam vos ipsos. Sumendum est in omnibus scutum fidei, in quo possitis omnia tela nequissimi ignea extinguere, sine fide enim impossible est placere Deo, victoria: fides vestra Galea quoque salutis capiti imponenda est, ut de solo Salvatore speretis salutem, qui salvum facit populum suum a peccatis eorum. Gladius autem spiritus, quod est verbum Dei, abundanter habitet in ore et in cordibus vestris, et quaecumque vobis agenda sunt, in verbo Domini fiant.
Saint Albert of Jerusalem
The Rule of Saint Albert, Chap. 18–19