Do you want to be happy? Who does not! Every human being on the planet, wants to be happy. But why is that? Because God designed man to be happy, from the very beginning.
If you think what kind of life, Adam and Even had, before they fell into sin. I am sure, they were enjoying themselves, in the garden of Eden. God had provided everything they needed, in that garden, all the nice food was there, and there was no any evil going on, around them, they felt safe, they were safe, they had all their needs supplied, and all the beautiful plants were around them.
There was nothing in the garden of Eden, to make Adam and Eve unhappy, depressed or worried, and they still did not know what evil was, because they had not fallen into sin yet. That was the original intention and design for mankind, from God, from the very beginning. Why should God change his intention today about that same design, he created, from the very beginning?
People everywhere, Christians or not, are looking for happiness. People without faith in God, do not know anything about the original design and intention of God, that God designed man, to be happy, from the start. So, they are looking for all sorts of things today, to make them happy.