St. Augustine said that the Old Testament is the New Testament veiled, and the New Testament is the Old Testament unveiled. We can see this in the five books of Moses, also known as the Torah or Pentateuch. These books explain how the Chosen People (Israel) came into existence, how God delivered them from Egypt, and the type of worship, social organization, and doctrines/morals He willed them to have. When interpreted allegorically, these five books point to the salvation of the individual Christian as lived in the Catholic Church:
1.) Backstory and promise. The Book of Genesis tells the backstory of the people of Israel, namely the history of the patriarchs and God’s promise to them. Every Christian has a backstory of God’s “promise” in their life before their conversion, an account of how God guarded and watched out for them when they were still far from Him. This is what we call prevenient grace.
2.) Conversion. The Book of Exodus tells how God delivered Israel from bondage in Egypt. This is the Christian’s story of conversion. Consider the Easter Vigil, in which Baptism, Confirmation, and the Eucharist are assimilated to the Passover narrative (or rather, the Passover narrative is revealed as a foreshadowing of the rites of Christian initiation).
3.) Liturgical worship. The Book of Leviticus tells how God established the Levitical priesthood to conduct the communal worship of Israel. I read once that St. Robert Bellarmine, S.J., a Doctor of the Church, identified three dimensions of unity within the Catholic Church: unity of belief, of government, and of communion. Leviticus points forward to the Church’s unity of communion expressed in liturgical worship. Having been converted to Christ, the Christian must join in the Church’s liturgical common life, most notably the Holy Sacrifice of the Mass offered by the new priesthood of Melchizedek.
4.) Ecclesial organization and government. The Book of Numbers tells how Israel was organized into tribes and clans. This corresponds to the Church’s unity of government. The Church is the one Mystical Body of Christ, and its members are organized into various provinces, dioceses, parishes, etc. Having been converted to Christ, the Christian must be subject to the Church’s duly constituted jurisdiction. As part of this, he must be enrolled in his parish.
5.) Doctrines and morals. The Book of Deuteronomy relates the last revelations that God gave to Moses regarding the sort of beliefs and morals Israel should observe. This corresponds to the Church’s unity of belief. Having been converted to Christ, the Christian must profess the dogmas that the Church propounds from the Deposit of Faith. The Christian must also obey the commandments of God and the Church.
Thus the story of Israel’s origin, liberation from Egypt, communal worship, organization, and doctrinal/moral teaching in the five books of Moses points forward to the life of the Christian lived out in the Catholic Church.