Saints

It's important to remember that saints aren't supernatural beings to be worshiped. In fact, in the New Testament, the term saint often is a synonym for Christian. We are all saints and are called again and again to become saints in our lives.  The word "saint" comes from the Latin word sanctus, meaning a holy one.

Why do Catholics pray to the Virgin Mary, the saints, and the angels?

Praying to Mary, the saints, and the angels can sound like trying to get "friends in high places" to run interference for you. Although people sometimes seek such "friends" in order to get a speeding ticket fixed, buy merchandise at a lower price or have some problem resolved, for Catholics that is not what devotion to the saints represents.

God alone is the source of all grace and blessing. Saints do not "fix" things for us apart from God or convince God to do X rather than Y. At Vatican II, the bishops taught that the holiness of the Church "is shown constantly in the fruits of grace which the Spirit produces in the faithful and so it must be" (Dogmatic Constitution on the Church, #39). Those "fruits of grace" are seen in the lives of saintly disciples, whether canonized or not.

Jesus was fully divine and fully human. As a human, Jesus could be only one gender, live at one time in history, grow up in one human culture, etc.  Saints help us to see holiness as possible for ourselves because saints include men and women, married and single people who lived at various times in human history and in various cultures. Saints remind us that, no matter what sacrifices we may need to make in order to cooperate with God's grace, we are not the first people to make those sacrifices. If we ask our friends on earth to pray for us, why not ask our friends in heaven to do the same?

-Franciscan Media

Many popular devotional practices involve veneration of the saints.  The saints have a special place in the Body of Christ, which includes both the living and the dead.  Through Christ we on earth remain in communion both with the saints in heaven and with the dead who are still in Purgatory. We can pray for those in Purgatory and ask the saints to pray for us. Through their prayers of intercession, the saints in heaven play an integral role in the life of the Church on earth. "For after they have been received into their heavenly home and are present to the Lord, through Him and with Him and in Him they do not cease to intercede with the Father for us, showing forth the merits which they won on earth through the one Mediator between God and man."  The saints, the members of the Church who have arrived at perfect union with Christ, join their wills to the will of God in praying for those in the Church who are still on their pilgrimage of faith.

Besides what the saints can do for us by their prayers, the very practice of venerating the saints does great good for those who are devoted to the saints. By practicing love of the saints we strengthen the unity of the entire Body of Christ in the Spirit.
This in turn brings us all closer to Christ. "For just as Christian communion among wayfarers brings us closer to Christ, so our companionship with the saints joins us to Christ, from Whom as from its Fountain and Head issues every grace and the very life of the people of God."
Love of the saints necessarily includes and leads to love of Christ and to love of the Holy Trinity. "For every genuine testimony of love shown by us to those in heaven, by its very nature tends toward and terminates in Christ who is the 'crown of all saints,' and through Him, in God Who is wonderful in his saints and is magnified in them."

—From Popular Devotional Practices