Genesis 1:1 In the beginning God created the heaven and the earth.
In the beginning… when the heaven and earth hadn’t been created, when God was all alone by Himself and no angels or elders sitting with Him.
The beginning denotes time, when years weren’t measured by the years of reigns of kings, when man didn’t know how to count the number of his days (rf. Psalms 90:12) but lived in the face of the earth till he died.
This beginning pre-empts eternity and maybe assumes it, so that there was no lapse of time between ‘eternity past’ and when the worlds (i.e. heaven and earth) were created.
This is the beginning God chose to create all things, when all things before had subsisted in Him and were in perfect harmony. This is the beginning, before Lucifer rebelled or before man fell, when everything was good and perfect.
In the beginning, God created the heaven and the earth, but He Himself was not created; only the Son was begotten in just one day. This shows the magnificence of God, how He had designed everything before time, and just laid them here for us to live in. This proves that all things subsist in God. All things begin in Him and end in Him. There is no end in Him because He continues forever.
NB: Though this is a commentary, I wrote it to educate believers.