Quantum mechanics is a highly successful and extensively tested scientific theory that provides a mathematical framework for describing the behavior of particles at the quantum level. It is true that quantum mechanics introduces probabilistic elements and non-local phenomena, such as entanglement, which can seem counterintuitive from a classical, deterministic perspective.
However, it is important to note that the lack of determinism or local causality at the quantum level does not necessarily imply the nonexistence of causality in a broader sense or rule out the possibility of a first cause. Causality as understood in classical physics may not apply at the quantum level, but that does not necessarily have implications for the concept of causality at other scales or in other contexts.
The question of whether God exists is a complex and multifaceted one that lies outside the scope of scientific inquiry alone. It is a philosophical, theological, and personal matter that encompasses a wide range of perspectives and beliefs. The existence of God is a question that involves considerations beyond the realm of scientific explanations, including faith, spirituality, personal experiences, and philosophical arguments.
Different individuals and cultures have various beliefs and interpretations regarding the existence of God, and these perspectives often extend beyond the scientific understanding of causality or quantum mechanics. It is ultimately a matter of personal belief and worldview.