I find it much easier to read the Bible when realizing that not all of it is going to agree. If I have to read it with the belief that it's inerrant, then it ends up looking incredibly schizophrenic to me.
For example, forms of Christianity teach that we are all depraved, cannot please God without Jesus, have no righteousness of our own, God hates us (unless Jesus intercedes), the Law is only meant to show how sinful one is, following the Law leads to death and self-righteousness and so forth.
Then I read a few Psalms:
Thou hast tested my heart and watched me all night long; thou hast assayed me and found in me no mind to evil. I will not speak of the deeds of men; I have taken good note of all thy sayings. I have not strayed thy path and never stumbled.
Psalms 17: 3-5
The Lord rewarded me as my righteousness deserved; my hands were clean, and he requited me. For I have followed the ways of the Lord and have not turned wickedly from my God; all his laws are before my eyes, I have not failed to follow his decrees. In his sight I was blameless and kept myself from willful sin; the Lord requited me as my righteousness deserved and the purity of my life in his eyes
Psalms 18: 20-24
The law of the Lord is perfect and revives the soul. The Lord's instruction never fails, and makes the simple wise. The precepts of the Lord are right and rejoice the heart. The commandment of the Lord shines clear and gives light to the eyes.
Psalms 19: 7-9
These are just a few examples. In other Psalms, we have the writer pleading with God to establish justice, for the writer's cause is innocent. Or stating that God will help the poor, the oppressed, the widows, and the orphans. And it's stated in such a way as though they deserve to be rescued by God -- aka, they don't deserve their current state of poverty or oppression.
And, yes, there are many Psalms where the writer is lamenting on his state of sin, and praying that God have mercy on him. But my question would then be if those Psalms are taken at literal face-value, to support a claim in man's sin-state, that has no goodness ... why can't the other Psalms also be taken at face-value, in terms of the writer stating that he's innocent, or he follows the law completely? What methods are there that would cause someone to take one literally, and the other figuratively?
Can we truly say that the Psalmist would agree that all people are wholly depraved, deserve nothing but eternal torment, lack any element that would please God, completely fail to follow a Law?