Why was Gabriel Marcel skeptical of attempts to prove God’s existence?

Gabriel Marcel was skeptical of attempts to prove the existence of God because he believed such intellectual arguments are exercises in primary reflection.1

In Marcel’s philosophy, primary reflection involves abstract, logical analysis that requires detachment from the subject matter to reach universal, objective solutions. He argued that while this approach is valuable for scientific or technical problems, it is fundamentally limited when applied to religious belief. Because the essence of faith is experiential and involves a personal, existential commitment, it belongs to the realm of mystery rather than the realm of problems.21

A mystery, for Marcel, is a question in which the individual is so deeply involved that they cannot separate themselves from it to study it objectively. By attempting to prove God’s existence through abstract reasoning, one necessarily precludes the direct, lived experience of God, as the move to abstraction excludes the individual’s personal involvement. Consequently, Marcel maintained that religious truth is accessed through a deeper, secondary reflection that honors the unity of human experience rather than through the detached analysis of primary reflection.21