I think atheism's big lie is that people's lives are better without God in it.
I have never met an atheist in real life or on the internet that believes their life is better without God in it. Being an atheist sucks ass. I know from personal experience. I have been a convinced Christian and I have been a convinced atheist. Life was so much better as a Christian.
Meth addicts would also assert that being high on meth is better than being sober. Being happy isn’t everything. We don’t just need happy people. We need responsible people in life too.
Even the Bible teaches us that there is a way that seemeth right unto a man but in the end leadeth to destruction.