In order to "judge" whether or not God displays omni-benevelence, you would have to be omni-benevelent yourself..... having explored all that is possibly good and it's fruit and declaring yourself as good. This would also require Omniscience.
Sometimes doctors haved learned to allow illnesses to ripen or mature like cataracts, before they are cut away and new sight is restored. An ignorant person may see the man suffering with the cataracts and falsely conclude that there are no doctors around. The wise man would maybe ask a few locals if this is so before concluding.
The gospels promise a knowing of your own salvation once a person is born again:
1 John 5: 13 - that ye may know that ye have eternal life
Atheists have no such promise of revelation. Once a believer receives this after being born again, he doesn't wonder whether or not God exists, these are questions the unregenerated entertain. He is given PROOF directly from the Source, and then goes on "prove to himself what is that good and acceptable and perfect will of God" as he walks and interacts with God on a daily basis. This is possible because that man is no longer God's enemy, having made peace through the blood value of Jesus' substitutional death in his place (not Adam's), and disowning himself as the New Testament Contract with God requires:
Luke 14: 31 - 35
"O r what king , going to make war against another king , sitteth not down first , and consulteth whether he be able with ten thousand to meet him that cometh against him with twenty thousand ? Or else , while the other is yet a great way off , he sendeth an ambassage , and desireth conditions of peace ."
Jesus is the King with twenty thousand, we are the "king" with only 10,000. The Romans were very practical and if the lesser king would simply pay the Roman tax, they could get the Roman war mechine to protect them from barbarians and everybody could go home. No so with Jesus; since his offer in the exchange is total, so is his price:
"S o likewise , whosoever he be of you that forsaketh not all that he hath , he cannot be my disciple .... He that hath ears to hear , let him hear . "
Only in this case can a person actually know what is good, having experienced and tested that omni-benevelence inside himself after the "new birth".
This is what happened to me and to millions of others that have taken up Jesus' offer to make peace with God. I am now much of the man that I always wanted to be thanks to the grace of God, and not due to any effort of my own.
"... not of works, lest any man should boast".