Fear God because He is dangerous.

There is no one or nothing more dangerous than God. That is why everyone must fear Him.

Consider at least four cases in the Bible of people being killed by God for incorrect worship.

Leviticus 10:1-2 KJV

[1] And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.

[2] And there went out fire from the LORD, and devoured them, and they died before the LORD.

2 Samuel 6:2-3,6-7 KJV

[2] And David arose, and went with all the people that were with him from Baale of Judah, to bring up from thence the ark of God, whose name is called by the name of the LORD of hosts that dwelleth between the cherubims.

[3] And they set the ark of God upon a new cart, and brought it out of the house of Abinadab that was in Gibeah: and Uzzah and Ahio, the sons of Abinadab, drave the new cart.

[6] And when they came to Nachon's threshingfloor, Uzzah put forth his hand to the ark of God, and took hold of it; for the oxen shook it.

[7] And the anger of the LORD was kindled against Uzzah; and God smote him there for his error; and there he died by the ark of God.

Acts 5:1-5 KJV

[1] But a certain man named Ananias, with Sapphira his wife, sold a possession,

[2] And kept back part of the price, his wife also being privy to it, and brought a certain part, and laid it at the apostles' feet.

[3] But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land?

[4] Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.

[5] And Ananias hearing these words fell down, and gave up the ghost: and great fear came on all them that heard these things.

[10] Then fell [SAPPHIRA] down straightway at his feet, and yielded up the ghost: and the young men came in, and found her dead, and, carrying her forth, buried her by her husband.

1 Corinthians 11:29-30 KJV

[29] For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord's body.

[30] For this cause many are weak and sickly among you, and many sleep.