My intent in this essay is to illustrate that the arguments regarding the existence of God and the fear of deception in Descartes' Meditations on First Philosophy are rather weak and they do not justify his conclusions. To support these claims, I will begin by outlining two specific meditations and explaining the proposed arguments. I will then critically analyze his arguments, revealing unfair conclusions. Doubts surrounding the text include the suggested characteristics of God, the condition of perfection, and the nature of deception. The conclusion will include a discussion of whether or not Descartes (also known as Renatus) succeeded in his plan. Most of Descartes' arguments regarding the existence of God occur in the third meditation. Having previously stripped himself of all material knowledge, all Renato can be certain of are his own ideas and that he is a “thinking thing” (35). Being a "thinking thing" speaks to its ability to create ideas, and that's really all that proves its existence to itself. Although he emphasizes that the ideas he conceives in his mind cannot be false, it is established that his application of such ideas in the form of judgments is prone to error (37). Furthermore, its ideas are classified as innate, adventitious, and man-made. Innate ideas are instinctive, uninfluenced truths; which are contrasted with the adventitious ideas learned through experience. The third thought process is invented ideas, such as imagination (38). These forms of ideas are necessary to the text because they are essentially the only known things that exist, and to categorize them is to define their origin. The tension is placed on the understanding of objective reality: the application of ideas influences... the medium of paper..., if it can be a deceiver. Because if I don't know, it seems I can never be completely sure of anything else” (36). The arguments he made regarding the existence of a Supreme Being may not have been very powerful, but their implications are fundamental to Renatus. In defining God, Renato learned the idea of ​​ultimate good, the conditions of perfection versus imperfection, the emotional "safety net" of religion, a commonality with another being, and had to confront the corruption associated with evil. Although his project also involved mathematics/geometry and the senses, their most useful application involved supporting his claims about God. In conclusion, although I do not believe that Descartes succeeded in his project, he would not have achieved a satisfactory end if he had not was so focused on the existence of God and the issue of deception..