Spiritually, "beginning" happens when we first start new growth -- new levels of awareness and willingness to receive goods and truths from the Lord, and use them. In the Word, "beginning" doesn't just mean the beginning of something in time. In the inner sense, it means the initial phase of a spiritual state.

The firmament of heaven represents mutual love. The firmament, as in Genesis 1, signifies the internal man.

(References: Arcana Coelestia 24)