Greetings, roman2819, I will have to respectfully disagree.
Rebirth on one level is indeed directly observable - my adult-self has been reborn from my child-self, and my child-self has been reborn from my infant-self, etc.
Rebirth on the other levels - the consciousness & mental continuums - are said in the early
Buddhist scriptures to require achievement of the fourth jhana in meditation (where the mind disassociates from the body) before one can directly observe rebirth happening across multiple physical lifetimes. The vast majority of individuals have not achieved the fourth jhana, much less the first, and so cannot observe these things.
If God is real, then the question becomes: "What is its nature, and is it truly the highest goal in life?" Based on what I have observed about life, my answer is "no".
How do attempts at answering the question about their existence address the more fundamental question about our purpose in life?
I haven't observed any of these things for myself, therefore I consider them hearsay and unprovable.
I believe I have had prayers answered in Buddhism as well.
If some of my prayers were answered by Buddhist devas, what does that say about prayer and the Christian god?