The Big Bang Theory (which I think is actually the Big Word of God reality) speculates that all existence was once compressed in a tiny thing the size of a pencil lead. For some "unknown" reason it “exploded” and in a Nanosecond the vast majority of existence was created.

The incarnation of Jesus, when He came to us, was the “Big Bang” in reverse. All the fullness of God was concentrated in Jesus. All that God is, dwells in Jesus. Like lightning in a bottle!