That we are eternal,that this physical realm and its carnal temptations are a deception to draw you further away from God, that the supernatural is in operation in all things, these are a few "ultimate truths" that the satanic cabal has kept from you and exploited to their own sole advantage.
Repent means, in simplest terms, "a change of direction." We have all been traveling headlong into Satan's embrace. Everything in our culture beckons to us and dismisses God as fantasy and outdated superstition. Meanwhile the satanists know perfectly well that there is a divine law, and they have chosen darkness. Most of us didn't know there was a legitimate choice, so we have opted for darkness too, largely unaware.
It takes a little while to wrap your head around it all, but I think of it now like a test during our short time in this earthly, fragile form. The satanists want us to choose the carnal, the physical, the fleeting, over God's eternal protection. Truly having faith in our eternal nature and God's love completely upends the satanist's plans here on Earth, because knowing the truth, why would I choose such carnal pleasures when there is ultimately a much better reward by traveling in the opposite direction. I use this time I have left here and this body for His glory now.
I'll add that for my whole life I was a devout atheist who never considered the possibility that I was living a life that drew me further away from God. I thought the idea was patently absurd, and that I wasn't really hurting anybody else or myself. If I can come to such a realization, that I was totally wrong, anyone can. I am His instrument now.
Romans 12
12 Therefore, I urge you, brothers and sisters, in view of God’s mercy, to offer your bodies as a living sacrifice, holy and pleasing to God—this is your true and proper worship. 2 Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is—his good, pleasing and perfect will.