By definition, the Christian God never came into existence; that is, He is the uncaused cause (Psalm 90:2). He was always in existence and He is the one who created space, time, and matter. This means that the Christian God is the uncaused cause, and is the ultimate creator. This eliminates the infinite regression problem.

Some may ask, "But who created God?" The answer is that by definition He is not created; He is eternal. He is the One who brought time, space, and matter into existence. Since the concept of causality deals with space, time, and matter, and since God is the one who brought space, time, and matter into existence, the concept of causality does not apply to God since it is something related to the reality of space, time, and matter. Since God is before space, time, and matter, the issue of causality does not apply to Him.

specific to this^^^
[link to carm.org]