1 Samuel 4-7 Ark Taken and Returned

What was the purpose of the ark? (review Ex. 25:1-22, espec. v.22)  How had it become an idol?  What happens to idols?  Why did Eli and his 2 sons die? (review 1 Sam. 2:27-36) What can God do with “idols”? (ch. 5)  What superstition was involved in returning the ark?  What tragedy also happened? (6:19)  What false idea did they develop concerning the ark?