Growing up Catholic I was taught about two gods. One was the tyrannical angry god of the Old Testament. The other was a god of love found in the New Testament. Of course this concept is incorrect.
We have one God, Yahweh. He is and always has been the same righteous, moral God. We have one Bible that, in the Hebrew and Greek, agrees between the testaments. Morality does not change.
As you read scripture look for the traits of God, Yahweh God.
Hebrews 13:8 “Jesus Christ is the same yesterday, today, and forever.”
John 10:30 I and my Father are one.
Isaiah 43:11 “I myself am Yahweh; and besides me there is no savior.”
Deuteronomy 10:16 “Circumcise therefore the foreskin of your heart, and be no more stiff-necked.”