how can you justify in your own mind what has been done by the RCC in the past, as you continue to go to Mass?
All religions have a dark side guided by the hand of men who have used them for personal gain. The mass on the other hand is a sign of hope and the means to an end established by JC Himself. If the mass has been perverted from that it doesn't show in history or the very basic purpose and ritual within the mass.
why did this god of yours give me a brain that questions his very existence?...
So, you can doubt. To doubt is to probe what we can to find truth. If you don't get the results you expect keep probing. Remember Thomas; who would have made a great scientist.
the millions of years that we have existed.
I hope you will limit that to two million as humanoid. H O M O sapiens only have 30k to their record.
why did your god leave them out from understanding him?
That is a good question but I doubt you will like the answer. The ontological question is always with us because the ontology says that you can't grasp the notion of God without being God.
That we need to ask your question is the only reflection of being both a physical being and a spiritual one. If we are both physical and spiritual them the spiritual part will exist for ever. Then death is only a transition. If there is no God, as you assert, then we just stop at death but our being will experience life forever. Then death is experienced by others. For us all experience stops.