The Ending?

Grand Master Undo Keir takes the Jesus DNA - found on the nails inside the Loculus - and has it spliced with his own DNA, the cells are used to develop an embryo, the embryo grows and is born, and is designated by the Vatican as Jesus Reborn, to be raised by Cardinal Modesto, and Modesto is really the Grand Master (remember, the Grand Master took over the Vatican).

Thus the anti-Christ is brought into the world.

Mira (a descendant of Mary/Magdalene) gives birth to a baby (father is Jake, a descendant of Jesus), and she hopes their baby will be the hope of mankind.

Thus the Second Coming of Christ is born into the world.

The babies are both born on the same day, 2000 years after the birth of Jesus, and during a rare conjunction of five planets.

Temp pretty much sums up the ending with one exception....if anyone notice...there was a huge meteor crossing in front of the five lights and destroys the Anti-Christ along with the Vatican with one go big hit a thousand miles away!
Look at the ending credits and you'll see mushroom cloud glowing red against the temple.
My take....
GGC's