Number Four (4) is the Gospel number in the Bible. Abraham, Isaac, Jacob and Joseph... were the Gospel in seed being sown in the ground of the fathers. God revealed Himself to them as El-shaddai... The exceedingly fruitful one. God sowed His Gospel seed in the fathers.
Exodus, Leviticus, Numbers and Deuteronomy...was the Gospel in shadows of the law. The Gospel in the stalk out of the blade of Genesis.
Matthew, Mark, Luke and John... the Gospel in earnest, in part, partially, in the earnest of the Spirit. The stalk brought forth flowers... the shuck and the tassel. The New Testament preached the Gospel in its flower stage.