Why wouldn’t we pray to Mary and the Saints?
Since Christ has but one body (1 Cor 12:20), not two bodies; one in heaven and one on earth, and since the saved are not separated from that one body by death (Rom 8:38), and since no part of that body can claim to not need another part** (1 Cor 12:21)** why would we presume it wrong to seek the prayerful assistance of the Church triumphant? (those in heaven).
St. Paul exhorted us to pray for one another** (1 Tim 2:1-2)** which he says is “good and…acceptable in the sight of God our Savior”. We are also told by St. James that “the prayer of a righteous man has great power in its effects”. Well who could be more righteous than our brothers and sisters in heaven? (James 5:16), who are not dead but are in fact, more alive than we? (Mk 12:27),
Confusion often arises in the minds of our Protestant brothers and sisters at the word “pray” which they typically use to denote “worship”. When we as Catholics use the word pray, we mean it in the traditional English sense - to ask. If you’ve ever read the King James Version of the Bible you may have run across the verse "I pray thee, say me not nay”** (1 Kgs. 2:20)**. It is clear from the context of this passage that Bathsheba is not worshiping her son Solomon, but asking something of him.
In the book of Revelation, we see that those who reside in Heaven are not merely praying with us but for us. Check out Revelation 8:3-4 and Revelation 5:8 This shouldn’t surprise us, as our brothers and sisters in heaven who surround us like a great cloud of witnesses (Heb 12:1) are more, not less, concerned for our well being than our Christian brothers and sisters on earth.