God is God. There are NO OTHER GODS except God.
Here, God introduces Himself, saying, " I [am] the LORD thy God, which have brought thee out of the land of Egypt, out of the house of bondage."
That way you know and understand WHO GOD IS. Where did God bring YOU out of? Was it an abusive relationship? Human slavery? Addiction? Prostitution? Pornography? Just plain meanness and cruelty? Rudeness? Crippling poverty? Sickness?
Everyone has an "Egypt". What was YOURS?
God then describes Himself. He is JEALOUS. He will not tolerate any attempt to replace Him with something in-animate, created by the creation HE established. He did not create the world and give us life and provision just to see us hold it in higher esteem than the ONE who GAVE it to you!
Has anyone ever experienced your parents catching you with a pack of cigarettes when you were younger, which was CLEARLY against their rules? Back in the old days, if a father caught his child with tobacco, he would take that child and give him a whole pack and make him smoke or chew it one after another until the child got sick.
God does that...not just with you, but your CHILDREN. The sin you commit will punish your children, and your grandchildren! God warns of this when He says, "for I the LORD thy God [am] a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth [generation] of them that hate me;"
Those "things" cannot fulfill your needs the way God desires to. And, if you continue to "worship" them, God will step back and let you do without what He desires for you to have until you realize the error of your ways. You will be made to WALLOW in the sins you commit, and your children will follow YOUR example!
However, those who, in the integrity of their hearts, and with all their ability, do whatever they can to follow after HIM, and to obey His commandments, He will honor. ("And shewing mercy unto thousands of them that love me, and keep my commandments.")
Law number ONE: Do not make something besides GOD your GOD!