I think most people have wrestled with these questions. I can only share my own "bouts" and hope you get something from them.

The Existence of God

Somewhere between the ages of 4 and 7 (I can't pin it down any closer than that), I had a moment when I became self-aware. I was lying on my bed, daydreaming, when it suddenly struck me that I was hearing words inside my head that I wasn't speaking. I wondered if I could see them, so I went over to the door mirror in my room. I stared at myself in the mirror, and raised my hand to my face. When I realized I'd raised my hand, I thought about how I had done so without effort. I stripped off my clothes for a closer examintion. I became very aware of thoughts, and moving different parts of my body. Then I realized things were going on in my body without thought--breathing, pulse. I was filled with awe at the complexity of who I was, and became certain that whoever or whatever had created me was truly remarkable. I now choose to call that Creator "God."

Afterlife

I became convinced of an afterlife (athough I haven't a clue what form) when my mother died. A year before, she had been diagnosed with breast cancer, and had a mastectomy. For her own reasons, she lied to me about the fact that it had mestatized, and I had no idea that cancer was killing her. She had told me she wanted to visit (she was in Missouri and I in California), but ended up in the hospital. I decided to visit her instead. It was only then that my sister admitted Mom was dying. The day that I was to leave, I was at the ocean collecting a jar of water to take to my mother when I very clearly felt her presence. She said "goodbye" to me, assured me that it was OK, and I felt her give me a hug. I raced back to my apartment and called my sister. She had not heard that Mom had died, so I thought I was wrong. Not 5 minutes later, she called back. My aunt had been trying to reach her while we were on the phone. My mother had died at precisely the time I felt her presence.