What really is Paganism at it's Root?
It is Inverting God's Plan.
For Example--
Environmentalism: Replacing the Dominion Mandate of Day 6 of 
Creation by flipping mankind under the rule of the environment rather than the environment ruled under mankind.
Marriage: Having men marry men and women marry women thereby inverting God's way.
Gender: Sowing Confusion about one's Gender and attempting to reverse one's gender.
Evolution: Rather than having the Creation come from the hand of God via His voice---it has the Creation appear over eons of time via the hand of chance. So instead of having mankind governed under his Creator---mankind has triumphed over the Creation therefore no need for a Creator.
Sabbath: Flips the day of Creation from the Day the Creation was Finished (7th day of the week) to the day it all began (1st day of the week).
Because that,
---when they knew God, they glorified him not as God,
---neither were thankful;
---but became vain in their imaginations, and their foolish heart was darkened.
Professing themselves to be wise, they became fools, And changed the glory of the uncorruptible God into an image made like to corruptible man, and to birds, and fourfooted beasts, and creeping things. 
---Wherefore God also gave them up to uncleanness through the lusts of their own hearts, to dishonor their own bodies between themselves: Who changed the truth of God into a lie, and worshiped and served the creature more than the Creator, who is blessed for ever.
For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature: And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet.
And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient; ...Being filled with all unrighteousness, fornication, wickedness,... Romans 1:21-29