The primary mark of the church, Holiness.

One of the main characteristics of the Catholic Church is her holiness. Not all members, leaders included, are de facto holy. The scandals that riddle catholic history prove that painfully enough. But the church as a whole is holy, because she's considered the bride of Christ, and also, the mystical body of Christ. Initially, members are capable of sinning, but as something founded by Christ himself to save souls, the church as a whole cant sin. Her sanctity is expressed in her daily prayer

All over the world, priests, deacons, sisters, brothers, seminarians, and laity pray the Liturgy of the hours, otherwise known as the Divine office or the Breviary. Mostly made up of the Psalms and including many other readings from the bible, this ancient collection and manner of praying goes back to the early and ancient church.

The holiness of the church is also experienced in the daily celebration of mass. Somewhere in the world every hour on the hour a mass is being celebrated. The church is also the guardian of the sacraments so that they're properly, validly, and reverently celebrated all over the world and all the time. As vehicles of grace, the sacraments sanctify Catholics every time they're received.

Often, someone will name a corrupt pope, bishop, or priest from history or more recent vintage as an argument against the holiness of the church. Just as you see invidual examples of a bad husband or a bad wife here and there, the institution of marriage isn't bad just become some married people can't fulfill their vows and maintain a permanent, faithful, fruitful, and loving relationship. Likewise, you've heard of abusive fathers or mothers who abandon their children, yet the institution of family isn't tainted or tarnished by the minority who don't live up to the...