Why do Catholics pray to saints?
Hi, Aaron! Thanks so much for your question. It's a good one!
The first thing I'd like to clarify is that Catholic Christians don't pray to the saints as though they were the ones who would answer our prayers directly, but we do ask the saints to intercede for us, just as we would ask other members of the Church on earth to keep us in prayer. We consider that all of the faithful, living and deceased, are part of the Church and therefore part of the communion of saints. For this reason, we would consider that the prayers of those who are already beholding God face to face in heavenly glory (and are therefore more firmly united to Christ) would have the power to bring about even greater fruit than the prayers of the living (since our attention is still divided between heavenly and earthly concerns).
As you probably have heard, there are patron saints of particular causes (usually related to something from their own earthly lives) and we Catholics like to ask them to pray for us for those things in particular. There are patron saints of everything, from music (St. Cecilia), to cancer (St. Peregrine), to addictions (St. Maximilian Kolbe), to finding your lost keys (St. Zita -- a good friend of mine!). Just as the saints did good through their prayers during their earthly lives, so they can help us through their powerful heavenly intercession.
The Catechism of the Catholic Church (a little compendium of all of the Catholic Church's basic teachings) says this:
956 The intercession of the saints. "Being more closely united to Christ, those who dwell in heaven fix the whole Church more firmly in holiness. . . . [T]hey do not cease to intercede with the Father for us, as they proffer the merits which they acquired on earth through the one mediator between God and men, Christ Jesus. . . . So by their fraternal concern is our weakness greatly helped."495
May I also heartily recommend the rest of the Catechism section on the Communion of Saints? It's an interesting read, which you can check out here.
As always, thanks for reading! I hope this has been helpful.
Peace and all good,