Why does anything exist ... why not nothing?

He is the image of the invisible God , the firstborn of all creation: for by Him all things were created, both in the heavens and on earth, visible and invisible, whether thrones, or dominions, or rulers, or authorities—all things have been created through Him and for Him. He is before all things, and in Him all things hold together. He is also the head of the body, the church; and He is the beginning, the firstborn from the dead, so that He Himself will come to have first place in everything. For it was the Father’s good pleasure for all the fullness to dwell in Him. - Colossians 1:15

Modern Epicureanism

A Creed of Modern Epicureanism
We believe that reality is worthy of honest inquiry.
We seek truth through observation, reason, experience, and the wisdom of
those who have gone before us, recognizing that what we know is always open to deeper understanding.
We accept the process of modern science and seek to understand the natural world without fear, superstition, or unnecessary certainty.
We believe that the material world is real, intelligible, and worthy of wonder, while remaining open to a reality beyond what science can measure.
We believe that creation has meaning, that human beings possess dignity, and that love, compassion, friendship, and service are greater treasures than wealth, status, or power.
We seek pleasure without excess, simplicity without deprivation, and freedom from desires that enslave us.
We will not fear nature, nor will we pretend to understand everything within it.
We will not fear death, though we acknowledge its mystery and its
seriousness, trusting that its meaning may extend beyond what we can
presently comprehend.
We seek to live peacefully with ourselves, generously with others, gratefully
within creation, and courageously in the presence of uncertainty.
We seek truth without fear, live with moderation, love generously, and
remain open to wonder.