"There is even a school of thought which argues that our own moon was made of materials knocked off the earth."
That is the prevailing school of thought, actually. The more accurate statement would be that the Moon is made up of the combined remains of the original impactor and some terrestrial debris. The composition of the moon, its orbit, and Earth's rotational inclination all support this theory.
Or, on the other hand, God could have just made it as it is, since it is so useful to life on Earth thanks to tidal forces and provision of simple calendric computations.
Since no one was there to see it happen, it really is just a matter of belief. It is impossible for naturalism to "proove" the ejectile origin of the Moon. "Was made" seems right to me.
We had the sky up there, all speckled with stars, and we used to lay on our backs and look up at them, and discuss about whether they was made or only just happened. Jim he allowed they was made, but I allowed they happened; I judged it would have took too long to MAKE so many. Jim said the moon could a LAID them; well, that looked kind of reasonable, so I didn't say nothing against it, because I've seen a frog lay most as many, so of course it could be done. We used to watch the stars that fell, too, and see them streak down. Jim allowed they'd got spoiled and was hove out of the nest.