Leviticus is a book of laws for the priesthood and the laity. It is also a book that explicitly instructs us to worship one God.
Lev. 11:44 For I am the LORD your God: ye shall therefore sanctify yourselves, and ye shall be holy; for I am holy: neither shall ye defile yourselves with any manner of creeping thing that creepeth upon the earth. 45 For I am the LORD that bringeth you up out of the land of Egypt, to be your God: ye shall therefore be holy, for I am holy.
LORD in both of the referenced scriptures above is the tetragrammaton (YHWH) referring to the one God of Israel. This name for God in the Old Testament occurred 6,823 times in the Biblia Hebraica and Biblia Hebraica Stuttgartensia which form the basis for the underlying Hebrew text of the Old Testament.
God, as read above, is a translation of elohim which, as noted in a previous post in this series is the plural form of Eloah and is used to delineate a plural of majesty or a plural of attributes in God. Notice the coupling of elohim and YHWH. YHWH is the name of the one true elohim of Israel.
Lev. 18:2 Speak unto the children of Israel, and say unto them, I am the LORD your God.
Lev. 18:4 Ye shall do my judgments, and keep mine ordinances, to walk therein: I am the LORD your God.
Again, we see the same pattern repeated in these scriptures too. All through scripture we see the God of Israel being a single entity. He is called YHWH or Yahweh in the Old Testament by Jews and Jesus Christ in the New Testament. There is no reference to a trinity or even a duality in God in the bible. The theology and doctrine taught by the scriptures is that of One God who came down to earth manifested in flesh to redeem a fallen mankind from their sin.

