Although the true God was always with the Jews, they worshipped false gods instead of the true God who brought them out of Egypt. Almost immediately they were free, Aaron was making the Golden Calf and saying to the people, "These be thy gods, O Israel, which brought thee up out of the land of Egypt." (Exo 32:4)
More examples of Yahweh commanding the making of sacrifice can be seen here.
Jeremiah 7:21 Thus says Yahweh of Armies, the God of Israel: Add your burnt offerings to your sacrifices, and eat meat.
Ezekiel 20:40 For in my holy mountain, in the mountain of the height of Israel, says the Lord Yahweh, there shall all the house of Israel, all of them, serve me in the land: there will I accept them, and there will I require your offerings, and the first fruits of your offerings, with all your holy things.
Ezekiel 44:15 But the priests the Levites, the sons of Zadok, who performed the duty of my sanctuary when the children of Israel went astray from me, they shall come near to me to minister to me; and they shall stand before me to offer to me the fat and the blood, says the Lord Yahweh:
This was in opposition to the true God to whom sacrifice is an abomination.
In every city of Judah he made high places to burn incense to other gods, and provoked to anger Yahweh, the God of his fathers. 2 Chronicles 28:25
“What to me is the multitude of your sacrifices? says the Lord; I have had enough of burnt offerings of rams and the fat of well-fed beasts; I do not delight in the blood of bulls, or of lambs, or of goats.(Isaiah 1:11)
Bring no more vain offerings; incense is an abomination to me. New moon and Sabbath and the calling of convocations—I cannot endure iniquity and solemn assembly. (Isaiah 1:13)
Thou shalt not do so unto the LORD thy God: for every abomination to the LORD, which he hateth, have they done unto their gods; for even their sons and their daughters they have burnt in the fire to their gods. (Deu 12:31 KJV)
Despite being told not to, they still continued to make sacrifice, even sacrificing their own children as you can see in the verse above.
Jesus said to them: "O Jerusalem, Jerusalem, which killest the prophets, and stonest them that are sent unto thee; how often would I have gathered thy children together, as a hen doth gather her brood under her wings, and ye would not!" (Luk 13:34)
Jesus is the true God of the Old Testament. They rejected Him in Old Testament days, they rejected Him in New Testament days, and they still reject him today, as we can see from your posts. Isaiah had it right when he wrote in Isa 9:6 "For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace."
Regarding the title of this thread, "Jesus is Jehovah?" The answer is a resounding YES. As soon as people realise this, they need to convert from their traditions and turn to Jesus.