The ontological argument, a rational proof for the existence of God, has been the subject of considerable debate, with multiple interpretations, formulations, and conflicting opinions surrounding it. That is because it is considered to be an a priori proof, based on the concept of "greatest" or "supreme being" (or equivalent terms), and from there, attempts to infer that God exists in reality-all without depending on the external world, or actual realities, or physical beings. Consequently, the ontological argument is considered a priori to empirical experience. Given the importance of this issue and its connection to ideological aspect, this article aims to shed light on the argument, examining the most significant formulations developed by various thinkers. It then evaluates the logical value of the principal objections raised against it by Immanuel Kant and engages in an objective analytical discussion of these objections, grounded in rational and demonstrative principles. Additionally, the article explores whether the ontological argument is a prerequisite for other rational proofs of God's existence, such that, if it were invalidated, the other arguments would also fail, or not.