Guardian Angels Unbiblical?

In the NT we can find many references to angels being sent by God to humans. As Scriptural proof of guardian angels I would point to Acts Chapter 12 where an angel frees Peter from prison and when he goes to the house of Mary, mother of John Mark, we read the following:

12 So, when he had considered this, he came to the house of Mary, the mother of John whose surname was Mark, where many were gathered together praying. 13 And as Peter knocked at the door of the gate, a girl named Rhoda came to answer. 14 When she recognized Peter’s voice, because of her gladness she did not open the gate, but ran in and announced that Peter stood before the gate. 15 But they said to her, “You are beside yourself!” Yet she kept insisting that it was so. So they said, “It is his angel.”

Acts 12:12-15 (New King James Version)

I even cite it in the Protestant NKJV version so no on can disbelieve it as being from a Catholic translation. It’s obvious that others in the house assumed that the voice at the door was Peter’s guardian angel because they believed Peter was in prison. It was actually Peter at their front door as he had been released from prison by an angel. God has sent us the Holy Spirit, but He still makes use of his messengers (which is what angel means in Greek.)

And if one needs Biblical proof consisting of word directly from the lips of our Lord I cite the following:

“Take heed that you do not despise one of these little ones, for I say to you that in heaven their angels always see the face of My Father who is in heaven.”

Matthew 18:10 (New King James Version)

This verse has traditionally been used as proof for belief in guardian angels. I’m not really sure how else the phrase “their angels” can be understood.

Here we have direct Biblical proof of belief in guardian angels. That’s more than can be said of any belief in Sola Scriptura.