God is jealous, and the LORD revengeth; the LORD revengeth, and is furious; the LORD will take vengeance on his adversaries, and he reserveth wrath for his enemies.
--Nahum 1:2

The sons of Eli weren't content with the portion the Lord provided for them. They wanted more, so much so they broke God's law. It is likely that seeing no condemnation from God, the sons of Eli continued their evil practices, which in time became custom.

Quoting from the Jamieson, Fausset and Brown commentary of 1 Samuel 2:13-17...

When persons wished to present a sacrifice of peace offering on the altar, the offering was brought in the first instance to the priest, and as the Lord’s part was burnt, the parts appropriated respectively to the priests and offerers were to be sodden. But Eli’s sons, unsatisfied with the breast and shoulder, which were the perquisites appointed to them by the divine law (Exo_29:27; Lev_7:31, Lev_7:32), not only claimed part of the offerer’s share, but rapaciously seized them previous to the sacred ceremony of heaving or waving (see on Lev_7:29); and moreover they committed the additional injustice of taking up with their fork those portions which they preferred, while still raw. Pious people revolted at such rapacious and profane encroachments on the dues of the altar, as well as what should have gone to constitute the family and social feast of the offerer. The truth is, the priests having become haughty and unwilling in many instances to accept invitations to those feasts, presents of meat were sent to them; and this, though done in courtesy at first, being, in course of time, established into a right, gave rise to all the rapacious keenness of Eli’s sons.

Perhaps the sons of Eli thought it easier to simply take the portions they desired rather than be bothered with an invitation to a feast. But God, by His own admission, is a jeasous God-- jealous of all things that are His. Even of His law.

So how to punish the sons of Eli? And demonstrate His glory to the heathen nations as well? The God who said, "Thou shalt have no other gods before me. Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth: Thou shalt not bow down thyself to them, nor serve them: 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; And shewing mercy unto thousands of them that love me, and keep my commandments." Is the same God who is bound by His word to perform that which He has decreed, and in this case He has decreed He will 'visit the iniquities... and show mercy' on those who disobey and obey, respectively. Simple enough.

In the fullness of time, the Children of Israel went out to war with the Philistines, and were soundly beaten. Not because of the sins of Israel-- for no mention of Israel's sins is made --but rather for the sins of the sons of Eli. The result was that four-thousand Israelites were killed by the Philistines.

Disheartened by this event the Israelites called for their secret weapon, the Ark of the Lord. The Philistines, hearing all the cheering from the Israeli camp, and realizing the Ark of the Lord would be used against them, they began to fear. But the Philistine generals rallied their troops and encouraged them. When battle was enjoined once again, thirty-thousand Israeli soldiers were dead, including the sons of Eli. And the Ark of the Lord was captured.

And the Philistines took the ark of God, and brought it from Ebenezer unto Ashdod. When the Philistines took the ark of God, they brought it into the house of Dagon, and set it by Dagon.

Now... The Ark of the Lord was 3 feet 9 inches in length, 2 feet 3 inches in breadth, and 2 feet 3 inches high-- not including the mercy seat with its golden Cherubims. Placed inside this Ark were the tablets containing the law delivered unto Moses on Mount Sinai; and reportedly, a bowl of manna, and the staff of Aaron. Even on a table the prescribed height of 2 feet 3 inches, the whole presentation-- not including the mercy seat and golden Cherubims was no more than 4 and one-half feet high. Assuming the mercy seat and Cherubims were no more than 15 inches high, we're looking at a total height of just under 5 and one-half feet from the ground to the Shekinah Glory of God.

And when they of Ashdod arose early on the morrow, behold, Dagon was fallen upon his face to the earth before the ark of the LORD. And they took Dagon, and set him in his place again.

'They' obviously denotes more than one. So the question now is, just how tall or large must an idol be that it would require more than one person to set it in place? That would depend on whether it was carved from stone, wood, cast in metal, or over-laid with metal, inwhich case it would take more than two to set the idol upright. Was Dagon set upon a pedestal? How tall was Dagon? Let's assume the image of Dagon was at least 5 and one-half feet tall-- I'm guessing it was taller --How much of an affront to the physical manifestation of God in the form of God's Shekinah Glory would it be for an idol to stand taller, or stand at all in God's holy presence? The men of Ashdod found out the very next morning.

And when they arose early on the morrow morning, behold, Dagon was fallen upon his face to the ground before the ark of the LORD; and the head of Dagon and both the palms of his hands were cut off upon the threshold; only the stump of Dagon was left to him.

On the second morning the men of Ashdod find Dagon making obeisence once more before the Ark of the Lord, this time sans head and hands.

God is a jealous God.

But the story doesn't end there. The Philistines, deciding the Ark of the Lord was not a safe thing to have lying about, decide to send it away to another city, but every where they send it the people suffer from a plague of emerods-- or boils (though the etymology of 'Emerod' shows the word is more akin to 'Hemorrhoid') and 1 Samuel 5:9 does say that God "...smote the men of the city, both small and great, and they had emerods in their secret parts."

Leaping ahead four-thousand (+/-) years, if God is indeed 'true, and every man a liar,' then he-- God, the Son --is returning soon. Why? To put an end to wickedness? Well... not quite yet. You see, with each earthly dispensation, God allowed men to rule themselves under specific criteria. First was the Dispensation of Innocence which ended in disaster with the expulsion of Adam and Eve from the Garden. Next came the dispensation of Conscience which also ended in disaster with Noah, and the flood. What came next was the dispensation of human/individual governance, and ends with with the calling of Abram, at which point the dispensation of Promise arrives but this in turn ends in disaster with the enslavement of Israel in Egypt. The fifth dispensation is that of Law, Followed by the sixth and present dispensation of Grace.

Each of these periods of testing have ended, more or less, with the failure of man to live up to the standards God has laid out, and this current dispensation is turning out to be a doozie. The point is, God is in the business of teaching men lessons. He taught the sons of Eli a hard lesson, and in turn the Philistines. He rewarded Israel and Judah's failures with captivity. And he will reward this present generation with God-only-knows-what... exactly. He is a jealous God, our Lord. He is jealous of the attentions we give to everything and everyone but Him.

The seventh and final dispensation, the Millennial Reign of Christ on earth, will also end with man's abject failure. It's as though God will say...'Okay, now. I've locked Satan away for a thousand years. You will live in peace, and enjoy my presense with you, please try to be good... You have no more excuses, if you fail, you'll have only yourselves to blame...'

But Satan will be loosed and men will once more rebel against God-- the seeds of that rebellion growing long before Satan is ever loosed. Again, God is in the business of teaching lessons. And many who were born during that period of one-thousand years will fail to accept Christ as savior and perish.

The lesson, of course, is 'You can do nothing apart from Me. I am the beginning and end of all things, for all things are either perfected in Me or cast into outer darkness.'

But let's go back for a moment to Dagon the headless, and extrapolate the simple truth that God is a jealous God, and always in the business of teaching lessons... even to idols, and especially those who worship such. How soon, therefore, before God cuts off the head of Islam? How soon before He punishes those who worship Allah? How soon before He does the same with every other false faith, and false god in this great wild world?

Perhaps today.

God is jealous, and the LORD revengeth; the LORD revengeth, and is furious; the LORD will take vengeance on his adversaries, and he reserveth wrath for his enemies.
--Nahum 1:2