If there is no God, then there is no such thing as Truth. If there is no ultimate truth (or falsehood!) then any searching for it is at best a waste of time. Then you have only data. You have nothing to give rise to science, except as data-gathering. But behind the data, there's no plan, no design, nothing to know. It's all just chance.
If there is no God, then there is no such thing as anything being good or bad. You may still have emotions, but they are entirely subjective; you cannot really experience anything as intrinsically good or bad, or as valuable or significant or meaningful. You moreover have no scale against which to recognize morality or immorality.
There's really nothing to think, nothing to know, nothing to feel, nothing to experience, so what's left? An infinite (maybe) void.
The heavens are telling the glory of God; and the firmament proclaims his handiwork.
Day to day pours forth speech, and night to night declares knowledge.
There is no speech, nor are there words; their voice is not heard;
yet their voice goes out through all the earth, and their words to the end of the world. Psalm 19:1-4