This claim that scientists that study these things don't have any idea how eggs evolved is pretty amusing to me in light of the fact that I just spent a few minutes finding just five references of the many available that indicate the state of knowledge of the evolutionary origin of eggs. Anyone can find this information. Any Christian can do it. One just did.
The first is the most recent and, to me, the most interesting.
Starck, J.M., J.R. Stewart & D.G. Blackburn. 2021. Phylogeny and evolutionary history of the amniote egg. J. Morphol. 282(7): 1080-1122.
Tihen, J.A. 1960. Comments on the origin of the amniote egg. Evolution. 14(4): 528-531.
Didier, G., O. Chabrol & M. Laurin. 2019. Parsimony‐based test for identifying changes in evolutionary trends for quantitative characters: implications for the origin of the amniotic egg. Cladistics. 35(5): 576-599.
Laurin, M., 2005. Embryo retention, character optimization, and the origin of the extra‐embryonic membranes of the amniotic egg. J. Nat. Hist. 39(34): 3151-3161.
Deeming, D.C. & M. Ruta. 2014. Egg shape changes at the theropod–bird transition, and a morphometric study of amniote eggs. Royal Society open science. 1(3): 140311.