religious symbols

You can't be certain that religions are all about greed and power. There could be other influences that you're not aware of. So you shouldn't use the word "know" there.

Also, you can't know for sure that all religions are imaginary.

Yes I can! Historians and Bible scholars are now just piecing together which ancient tales are employed in the collection we now call "Bible"! Religio came about as a result of a compulsion to have answers. The afterlife came about from unscrupulous rulers getting youth to offer their lives. Trying to rescue the failed cults is a crime against humanity.

Nice try. But you weren't there when religion was developed, so obviously you can't be certain whether it was brought about by the motives you're saying, or for different motives.

Since you're not certain about the influences that contributed to religion, you shouldn't use the word "know" when you're asserting that it's all about greed and power.

Your meme would be better if it used words such as "I believe" or "my opinion is."