The present god mankind adores seems to be less than perfect. It is another thing that only a portion of humanity knows him or follows his precepts. There are millions who are atheists, pantheists or following primitive religions.
By definition, God should be that, greater or more perfect than which there can be nothing. But the present god, the Judeo-Christian one is full of imperfections. He is selfish, cruel and demonic. (He chose a particular tribe to reveal himself and He destroys others for the chosen ones. He is pictured as a cruel, angry and selfish god in the Old Testament. Just look at the way he sends innumerable plagues to the Egyptians to let the Israelites go. At last he sends his angels with a burning sword to butcher the entire first born of the Egyptians. Can there be greater cruelty?)
There has been evil ever since the beginning of this world. Since the creation of man he has been put to all sorts of hardships, pain, suffering and death. Look into the history of natural calamities (Acts of God) like quakes, floods, volcanic eruptions, plagues hurricanes, droughts and innumerable other natural calamities in which millions and millions have perished. The bubonic plague which gripped Europe a few centuries back killed more than 20 million people!
Man has always been haunted by diseases, wants pain and suffering caused by evil which this god permits to happen. Hence evil exists in Him.
Naturally there should be another god who has no evil in him, as a being without evil is more perfect than one with evil. And he should exist as existence is more perfect than non-existence. Let us search and wait for him