You and I exist, but we might not have. Humans exist, but they might not have. The earth and other planets exist, but they might not have. Our universe exists, but it might not have. Phew, that's enough. Seemingly, everything that exists might not have.
Neither we, humans, the Earth, or the universe is the explanation of its own existence. My existence was contingent upon something else--my parents. I am a receiver of existence. So are my parents.
It is impossible to conceive of a universe in which all things are receivers of existence. It's easy to realize this when we put it into terms. If all things which existed were receivers of existence, it would go on forever. One might ask, "What's the problem with this? Can't there be an infinite number of events before right now?" The answer is simply, "No." That would mean we counted through an infinite number of events to reach right now. It is impossible to count to infinite.
The Need for a Giver
Logic requires a starting point, or a giver. Contingent existence requires that something exists in its own right. It "is". For simplicity sake, let's refer to this being as the "giver".
Often, I hear, "But, what accounts for the giver's existence? Where does the giver come from?" The answer is something you will have to follow closely. Since this giver is not contingent, the source of the giver's existence is contained within the giver itself. This means there is something about what the giver is that requires its exist. "What" something is refers to the nature of a being. My nature is human, which means I possess certain qualities. One is that I am contingent. We may, or may not exist. The giver on the other hand must exist. The giver cannot not exist. The giver, is existence. This is the Primary Truth about "the giver".
(As a side note, it might shock some of you to know philosophers realized this 5 centuries before Christ).
What This Tells Us about Our Giver
Some of you are saying, "So what? That doesn't mean a whole lot. So there's a reason we all exist. It doesn't tell us anything about this 'giver person'."
One thing we can know is that the giver exists without limit. There is no deficiency about being. Deficiencies are that which are not. The giver exists to the fullest of existence. The giver is infinite. This means the giver exists in the perfections of all things. For instance, the giver could not make something exist that the giver is not. Since we can see and hear, we know that the giver can see all and hear all. Furthermore, knowledge and charity are found in created things. This means the giver must know all and love all. That means the cosmic being, far away from us in the order of existence, is also close and personal with us. It knows and loves us.
For Today, This is What We Know
1. We are contingent, and contingent beings require one who is not contingent.
2. A being that is not contingent has a nature requiring that it is existence.
3. A being that is, must exist to the fullest extent of that which are.
4. Perfections which exist in nature, must exist in the giver. (ex: love and knowledge).
5. The giver of our existence knows and loves us.
Let that sink in for a moment, this much is knowable without Sacred Scripture, and was developed by people that did not know or follow the Judeo-Christian religions.