May is the month of Mary, and a question that often comes up is about the intercession of Mary and the saints. People often ask what's the point of it, since we can pray directly to God.
Yes, we can and certainly do pray directly to God. So it's not a matter or either/or.
It's a both/and.
St. Thomas makes an interesting point about this. I'm paraphrasing a bit, but basically he says that we can become like God in two ways. First, because God is good, we become like him by being good. Second, because God is the cause of goodness in creatures, we become like God by bringing goodness to others, by doing good. (Summa Theol., I, q. 103, a. 4).
That second point is the key thing in regard to the intercession of the saints. By praying for us, they play a role in bringing goodness to us. It's part of God's plan. It's more perfect for us to reflect God's goodness by doing good, rather than simply by being good. We're meant to be active, to reach out, to help others, and that reflects God. The intercession of the saints does precisely that.
When you think about it, isn't that how God acts in regard to other things? Couldn't he have just directly created all the people he wants, instead of having them come into the world through their parents? Sure, he has the power to do that if desired. But by giving parents a role in procreation, God is acting through them to bring goodness to others. And the parents play a very important role.
And that's good for us, because it's an important part of the way we become holy. We reflect these two aspects of God by both being good and doing good.