This is ultimately what humanism is. Man becomes God. Man decides what is morally acceptable and what is not. The adage of, "if it feels good, do it" becomes a ruling philosophy. The devil not only seeks to make you doubt God and not believe His Word, but ultimately his goal is to drag you away from God. Take a look at the world today and what you see is the result of this plan. A world that is content to make it up as it goes along. Not concerning itself with eternity.
God has an eternal plan beloved. His plan goes beyond this life which is aptly described in the Bible as but a vapor. Yet despite the vaporous nature, we seek to hold onto this life and what the world offers, grasping at the air furiously. Ecclesiastes paints the picture for us:
I, the Teacher, was king over Israel in Jerusalem. I devoted myself to study and to explore by wisdom all that is done under heaven. What a heavy burden God has laid on men! I have seen all the things that are done under the sun; all of them are meaningless, a chasing after the wind. Ecclesiastes 1: 12-14
Yet there we go, chasing after the wind nonetheless. The design of the enemy is to get us to not think eternally, but temporally. The enemy seeks to have us value this life and the things of this world as opposed to the promises God has already made to us. Temporal prosperity pales in comparison to eternal life:
Do not be overawed when a man grows rich, when the splendor of his house increases; for he will take nothing with him when he dies, his splendor will not descend with him. Though while he lived he counted himself blessed-- and men praise you when you prosper- he will join the generation of his fathers, who will never see the light of life. A man who has riches without understanding is like the beasts that perish. Psalm 49:16-20
Know your enemy beloved. The devil is not a cute caricature in a red jump suit and a pitchfork. The truth is that is what he wants you to think of him as. Or better yet that he doesn't exist at all. He has the majority of the world convinced of that. The result is they are content to be their own Gods; without a thought about the consequences awaiting them when their life will be required of them.
Your enemy is the father of all lies. He has not changed his tactics over thousands of years because he does not have to. What worked on Eve in the Garden of Eden still works too easily on us today. We see the waves and feel the wind and then start to listen to the whispering of the enemy. Just a little lie mixed in with the truth. Just enough to get our attention and start to doubt God. A foothold is established. Soon the enemy will seek to expand that foothold and get us to no longer believe what God has already said. If the stronghold grows too large, we can replace God with our own rationale our own understanding.
God has not left us unarmed though. His Word is our sword. We need to wield it against the lies of the enemy and take every thought that is set up in opposition to God and make it obedient to Christ. By avoiding the foothold, there will be no stronghold. There is no conversation to be had with the father of lies. Stay true to what you know. Stay true to the truth. It will always set you free.