Well, there's essential visibility and actual visibility...By the corporeal nature of the Sacrament itself makes the membership in the Church essentially visible, even if it's not known by anyone that this individual became incorporated into the Church.
Good point.
Of course He can, but He has worked outside the normal in some cases, such as when saints have raised individuals back to life to baptize them, for various reasons of His, most likely to reinforce the necessity of the Sacrament of Baptism. St. Thomas wrote that God might send a preacher miraculously to someone in the jungle who did not place any obstacles to receiving the faith, and we have stories about Mary of Agreda bilocating to the New World to evangelize the Native Americans. So who's to know how or why God chooses to take one or another path at any given time?
Yes, this was my poorly-explained point. I agree. I was trying to say that God gave us the Church and He will stick within its rules, even when He works miracles. He won't work miracles which require a change or the creation of new rules, because that would
a) undermine the original rules, which means they were flawed in some way, which is impossible, because God is perfect.
b) admit God needs to change, even when He's unchanging, and this is impossible, because God is eternal and knows all things.
c) admit God could not foresee the current circuмstances, or plan for it, so He's not omnipotent.
Example:
There are many saint stories where food was scarce and villiages/families were starving. The saints did not pray that God would miraculously "suspend the need for food" (this would be praying for a
change in the rules/necessity of human nature). No, the saints simply prayed for actual food (this miracle corresponds with the existing rules of nature that God already created...i.e. that humans need food to survive).
Example 2:
Raising someone from the dead to be baptized temporarily suspends the natural order of life/dying, but God used this to keep 100% intact the
spiritual order of the sacrament of baptism, which requires water. He did not change/alter the requirement for water (this would've been a change to Church rules). He worked a natural miracle (He suspended the laws of nature) to keep the supernatural laws pure and unchanging. Supernatural order > natural order.
Example 3:
Same thing with the bi-location of the nun to teach the Indians. Why didn't God just give each Indian a vision and teach them the Faith Himself? He could've infused knowledge into their souls and miraculously baptized them in an instant. *boom*. He reads hearts and knows if they wanted baptism. Why didn't He do this? Because He already established the rules of His Church, in His eternal and wise providence. And He established that humans typically learn from humans because we are visible creatures with a finite intelligence. And the Church is visible and sacraments require VISIBLE signs.
If God just went around "enlightening" everyone, then what need is there for His Church? Why would God be in competition with Himself? He wouldn't.