Why do Catholics keep relics?

A dead man is thrown into the prophet Elisha's tomb, touches his bones, and comes back to life.

Handkerchiefs and aprons that had touched Paul were brought to the sick, and they were healed.

A woman touches the fringe of Jesus' cloak and is healed — and Jesus tells her that her faith has made her well.

After Polycarp's martyrdom (c. 155), the Christians of Smyrna gathered his bones and laid them in a fitting place, to celebrate the anniversary of his death.

Christians celebrated the Eucharist at martyrs' tombs, and altars came to be built over them.

In the Middle Ages there were abuses: false relics and a trade in them. The Council of Trent (1563) condemned superstition and any search for profit.

The veneration of relics is one of the forms of popular piety that the Church encourages, as long as it leads to Christ.

It is absolutely forbidden to sell sacred relics.

The Church does not require belief in any particular relic; authentication is a historical question.