Light And Lights

Vos estis lux mundi... Lux utique ideo sunt vocati, quia, veritatis lucem percipientes, in Christi corpore per gratiam sunt assumpti. Ex quo et Apostolus: Fuistis enim aliquando tenebrae, nunc autem lux in Domino. Luminis enim natura est, quocunque inferatur, ut tenebras foras mittat: ita Apostoli, lux in Domino effecti, quia mundus extra cognitionem Dei positus tenebris ignorantiae caecabatur, positi sunt per eos omnes illuminentur. Hinc quoque Propheta de Christo vel ex persona quorumlibet signantur ait, Posui te in lucem gentium, ut sit salus mea usque ad extremum terrae. In lucem itaque sunt cum ad illuminationem fidei diriguntur, salus vero cum ad sanitatem. Et ideo sal eos esse supra commemorat, ut eorum sapientia corrupta sanentur. Siquidem per illuminationem gratiae lux dicuntur, ut illorum illustratione ab humanis cordibus tenebrae pellantur. Quod et Propheta de Domino: Dominus illuminatio mea et salus mea. Sanctus Paschasius Radbertus Corbeiensis, Expositio In Evangelium Matthaei, Liber III Source:Migne PL 120.233b-c

You are the light of the world...1 They are called light because they perceive the light of truth, receiving it in the body of Christ through grace. Whence the Apostle says, 'You were once in darkness, but now in the light of the Lord.' 2 For it is the nature of light, that wherever it is brought, it drives out darkness, and so the Apostles are made light in the Lord, and since the world is set outside the knowledge of God, blind in the ignorance of its darkness, so they are placed there that all be illuminated through them. So also the Prophet says concerning Christ, or signifying them by His person: 'I have placed you as a light to the nations, that my salvation may reach to the ends of the earth.' 3 Thus they are in the light when they are directed to the illumination of faith, and saved when brought to health. And therefore they are previously named salt, for their wisdom restores corruption. Indeed they are named light by the illumination of grace, that by their light darkness be expelled from human hearts. Whence the Prophet says concerning the Lord: 'Lord, my light and my salvation.' 4 Saint Paschasius Radbertus, Commentary On The Gospel of Saint Matthew, Book 3 1 Mt 5.14 2 Ephes 5.8 3 Mt 5.13 4 Ps 26.1