Apparently you missed that this (Psalm 119) is not a Psalm of David, at least there is no heading advertising it as such, and therefore it is not tainted by having been written by a murderer, adultery, and polygammist so far as we know. But there is more:

The only passage of Scripture that describes Scripture as inspired is 2nd Timothy 3:16-17, so lets take a look at what it says the PURPOSE of inspiration is exactly. Paul says “All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works.”

First, Paul says “All scripture is given by inspiration of God, and is profitable” not “and is inerrant.” That is the first point, that Paul himself recommends Scripture not on the basis that it can never be wrong, but on the basis that it is profitable. Secondly, for what is it profitable? To make the man of God perfectly equipped for every good work. That in Scripture which does not conduce to good works but is a hindrance to them, that which does not tend to make men righteous but unrighteous, that which makes men blame their sins on God rather than take responsibility and repent, is wrong and is only profitable towards the end goal of making the man of God perfectly equipped for every good work in the negative sense of “don’t follow this example!” So, when David blames God for his sin, the only profit to be derived from such as Scripture (for all Scripture is profitable) toward the goal of being equipped for good works, is to be on guard against such foolish sentiments knowing that men of the past who were considered by men to be pious made such grievous errors and destroyed their lives and the lives of those around them (look at David’s family).

Of what profit can David’s lie in Psalm 51:4 be “Against thee, thee only, have I sinned, and done this evil in thy sight: that thou mightest be justified when thou speakest, and be clear when thou judgest”??? Every scoundrel would merely repeat these words and say their sin is OK because it increases God’s judgment against them and therefore their evil was gone for good. Rightly does Paul chide the Jews at Rome for using this Scripture in that way, when he says “For if the truth of God hath more abounded through my lie unto his glory; why yet am I also judged as a sinner? And not rather, (as we be slanderously reported, and as some affirm that we say,) Let us do evil, that good may come? whose damnation is just.” (Romans 3:7-8)

In Short, because Calvinism reads 2nd Timothy 3:16-17 totally wrong, as though it said “All scripture is given by inspiration of God, and is inerrant” rather than what it actually says, “All scripture is given by inspiration of God, and is profitable…That the man of God may be perfect, thoroughly furnished unto all good works”–because of this, Calvinism has made it its especial goal to mine every wrong statement that exists in the Scriptures and set them up as an antichristian phalanx!!! Your view of Scripture is not the same as Paul’s. Had Paul mean to says that Scripture is infallible rather than profitable, he would have so said. But Scripture is only profitable and not infallible, for indeed some of the time the only profit that can be derived from a passage is its refuted by another passage! “But this view will create CHAOS in interpreting Scripture?” No, it will not, for the overriding rule to the interpretation is laid down by Paul as the ultimate purpose of Scripture itself, “That the man of God may be perfect, thoroughly furnished unto all good works.” Blaming man’s sins on God does not equip anyone to good works, but declaring plainly that man is able to repent on his own (as in Ezekiel 18) does equip men to good works! This is the rule. Calvinism makes men first into atheists out of disgust against its view of God, and then turns them from atheists to marginal God-hating relionists whose sole purpose is to deny that men can amend and to convince everyone that they are not able to do good and might as well stay sinners because they can’t possibly do any better. But the profit of Scripture, Paul says, is the opposite, to equip men to good works. Calvinism even while taking the Scripture to be infallible, can never be consistent, because its goal is not the goal of Scripture! Its goal is not to equip to good works but to deny that men can do good works! But when one accepts the same view of inspiration as Paul, then and only then can they and their interpretation be in line with the goal of Scripture, i.e. equipping men to good works.

If I hated God, I would be a Calvinist: What better way to show your hatred of God that to declare him the first cause of evil! But if you judge rightly that a polygamist, adultering murderer loves God more than I who have never murdered anyone nor stolen anyone’s wife, then what a strange knot your mind must be twisted into.