Outside intercession through prayer how can Mary and Saint’s protect us and what is the Theology and Scripture that explains and defends this?
If you have saints praying for you, they are protecting you. And if saints can be sent on missions like angels, they can protect people like angels do, too. And we see in Maccabees that Jeremiah was sent into Judah Maccabee’s dreams to give him a message and a sign, just like a messenger angel. God also sent Moses and Elijah to greet Jesus and talk to Him at the Transfiguration.
This is a very old belief. For example, Jewish women have pretty much always prayed at Rachel’s tomb for help in childbirth and in other women’s concerns, and Christian and Muslim women in the Holy Land do the same thing.
We see in the Bible that the bones of Elisha could even raise the dead. And God granted that. (2 Kings 13:21)
Since we know even better than the Jews of old that our holy dead are alive in Christ, there is no reason to believe that they aren’t doing things for us as well as praying for us. They are part of the Body of Christ, so He can use them as His Right Hand if He wants to.