I thought you might be interested in an excerpt from a treatise from Rene' Decartes':
Section 2 of my book "The Strength in Knowing', I discuss spirituality and how and why God must exist. In the following excerpt Decartes' explains how God must and does exist.
Descartes’ Meditations on First Philosophy
René Descartes’ Meditations on First Philosophy (1641) is a treatise which is dedicated to the Theology Faculty of the University of Paris. Descartes says that the treatise has two objectives: 1) to show that the soul is immortal and that God exists, and 2) to show that these assertions are truths which are logically necessary and which can be proved by reason.
Meditations on First Philosophy (1641) is a treatise which is dedicated to the Theology Faculty of the University of Paris.
Descartes argues that the idea of something which exists must be caused by something which exists. Something which exists cannot be caused by something which does not exist. A thing or being must have some actual or formal existence in order to cause another thing or being to exist.