Seal of God is Truth.
Bereishit (Genesis 1:1-6:8 )
In the beginning of God's creating the heavens and the earth... God blessed the seventh day and sanctified it because on it He abstained from all His work which God created to make
These two verses encompass all of Creation. The opening three words end in the letters taf, aleph, mem, which spell emet – truth, and the closing three words end in aleph, mem, taf, which again spell emet. Rabbi Simchah Bunim of P'shis'che cites the Talmudic statement, “The seal of God is emet”, and comments, “It is customary for an author to place his name in the opening of his book. God placed His Name emet – truth, in the opening chapter of the Torah. Emet thus envelops all of creation, a testimony to God as the Creator.”
Divrei Shaul notes that all traits can be a matter of degree. There can be greater beauty and lesser beauty, greater wisdom and lesser wisdom, greater strength and lesser strength, etc. Only one trait cannot be more or less: truth. There is no such thing as greater truth and lesser truth. Something is either true or it is not true.
God is identified with truth. Just as truth can never be altered, because altered truth is no longer truth, there can be no change in God. (Malachi,2:6).
The Talmud says that emet is broad-based, consisting of the first letter of the alphabet, aleph, the middle letter, mem, and the last letter, taf (Shabbos 55a). Truth therefore,has stability and durability. Falsehood, on the other hand, is the Hebrew sheker, consisting of three letters near the end of the alphabet. Sheker is top-heavy and cannot endure.
To the extent that a person lives with truth is the extent one identifies with God. Any falsehood distances a person from God.