Catholics do not worship saints; the veneration of the saints is good
It is clearly wrong to worship anyone other than God Himself. Our Lord said to the devil when he tempted Him: “It is written, the Lord thy God shalt thou adore, and Him only shalt thou serve” (Matt. iv. 10). When Tobias and his family prostrated themselves before the angel, he said “Bless ye God, sing praises to Him” (Tob. xii. 18). When St. John fell before the feet of the angel, the angel said to him “See thou do it not, adore God” (Apoc. xix. 10). If I am in the presence of a person of distinction or importance, it would be showing contempt for him were I to turn away from him, and devote my attention to someone inferior; so it would not be right to engross our mind and thoughts with any object in the place of God.
It is however no sin to reverence creatures in whom the perfections of God are reflected. We do not worship them with supreme worship; for we know that, however superior they are to ourselves, they are only creatures like ourselves; we only honour and venerate them for God’s sake. To have an image of a saint displayed in church or in one’s home is to show our respect and love for them; in the same way that we might have a photograph of a loved one displayed. There is great profit to be had from studying the lives of the saints to see how they reacted and behaved in certain situations, their heroic virtue and conduct inspires and teaches us to serve God more perfectly; as they did. We owe especial veneration to some of the saints who have rendered signal services to mankind; for example St. Patrick for his labours, efforts and sacrifices on behalf of the Irish people, St. Boniface who was instrumental in converting the pagans of Germany to the service of God; St. Ignatius of Loyola who maintained and defended the faith at a difficult time in history, St. Augustine who enriched the church with his writings etc. There are countless such examples. Our Lord Himself declared that to despise His apostles was tantamount to despising Himself (Luke x. 16) and He is not offended when respect and veneration is shown to His mother, His apostles or His saints; for their sanctity is a reflection of God’s greatness and is the product of His grace. Veneration of the saints does not detract in any way from but only increases God’s glory.
There is therefore nothing wrong in venerating the saints for the purpose of leading us closer to God; there is no better veneration of the saints than by imitating their virtues.
It is advisable under certain circumstances of life to invoke certain saints in times of special need. For example, we invoke St. Joseph as the patron of a happy death because he expired in the arms of Jesus and Mary; we also invoke St. Joseph at times of temporal distress for on him the child Jesus was dependant for His maintenance. St. Blase miraculously cured a boy afflicted with a throat disease and so he is invoked for diseases of the throat. For diseases of the eye, we call upon St. Ottilia because, though blind; she recovered her sight when she was baptised. Those who suffer through calumny find a protector in St. John Nepomucene, who was a martyr to the seal of confession; and when anything is lost, we have recourse to St. Anthony, through whose prayers the thief who had stolen from him a valuable manuscript, had no peace until he restored it. It appears that God has given to individual saints special powers to help us in special needs. May wonderful answers to prayer lead to the belief that the saints take particular interest in persons whose circumstances are the same as theirs were on earth, or whose calling or state of life was the same as their own was, or who live in the same place as they lived in or laboured in.