I often exist in the 3rd perspective within my mind. From there I exercise judgement on myself and all that is. Since I am not myself, I think I see things more objectively. I arrive at what I believe to be true about myself and reality. Then I experience life from there. This may sound arrogant which I am but I cannot deny that perspective.
You just stated a faith!
And you told us before you have no faith.
Seriously, you have faith that this perspective within your mind gives you an accurate picture of yourself and reality.
Most of us check our private perspective with the perspective of others. If you have a person whose private perspective tells him that he is Napoleon Bonaparte, when everyone else's perspective tells us Napoleon has been dead for nearly 200 years, then we say that the person is insane.
Judaism and Christianity are historical religions, as well as personal ones. By "historical", I mean the religions are based upon God's intervention in human history. For Jews, the essential intervention is the Exodus. For Christians, the essential intervention is the birth, life, death, and
resurrection of Jesus. As Paul said, if Jesus was not resurrected, then our faith is in vain.
The "historical" means that we have faith that the accounts of those who witnessed that intervention, then told others (who wrote it down) is
essentially accurate. We have faith that the gospels do relate actual events in Jesus' life, most particularly, the tomb was really empty.
The personal part of the religions is that each of us can (and hopefully does) have a personal, ongoing communication and relationship with God. For you, that
might mean that "the 3rd perspective within my mind" is God talking to you.
Some people have written down what they have learned from their personal relationship. In particular, Christians rely upon what the non-gospel writers wrote about their personal relationship with God. We have faith that those letters do contain accurate messages from God. After all, those letters -- combined with the gospels and their reason -- led the early Church Fathers to conclude Trinity.