From this Sunday’s second reading:
Paul… to the church of God that is in Corinth, to you who have been sanctified in Christ Jesus, called to be holy…
From the Second Vatican Council:
All the faithful of Christ, of whatever rank or status, are called to the fullness of the Christian life and to the perfection of charity; by this holiness a more human manner of living is promoted in this earthly society. In order that the faithful may reach this perfection, they must use their strength accordingly as they have received it, as a gift from Christ. They must follow in His footsteps and conform themselves to His image, seeking the will of the Father in all things. They must devote themselves with all their being to the glory of God and the service of their neighbor. In this way, the holiness of the People of God will grow into an abundant harvest of good, as is admirably shown by the life of so many saints in the Church’s history.
The classes and duties of life are many, but holiness is one – that sanctity which is cultivated by all who are moved by the Spirit of God, obey the voice of the Father, and worship God the Father in spirit and in truth. These people follow the poor Christ, the humble and cross-bearing Christ in order to be worthy of being sharers in His glory. Every person must walk unhesitatingly according to his own personal gifts and duties in the path of living faith, which arouses hope and works through charity. […]
All Christ’s faithful, whatever be the conditions, duties, and circumstances of their lives – and by means of all of these things – will daily increase in holiness, if they receive all things with faith from the hand of their heavenly Father, and if they cooperate with the divine will. In this temporal service, they will manifest to all men the love with which God loved the world. […]
Therefore, all the faithful of Christ are invited to strive for the holiness and perfection of their own proper state. Indeed they have an obligation so to strive. Let all, then, have care that they guide aright their own deepest sentiments of soul. Let neither the use of the things of this world nor attachment to riches, which is against the spirit of evangelical poverty, hinder them in their quest for perfect love. Let them heed the admonition of the Apostle to those who use this world; let them not come to terms with this world; for this world, as we see it, is passing away.