“Ah,” they say, “You are wrong. Psalm 51:5 says, ‘Behold, in iniquity I was born, and in sin my mother conceived me’ (LEB). See, man is sinful from birth which means he is unable to respond to God.” Oh Lord, my creator, I fall before you. I submit my mind to you. You guide my thoughts and my mind. You open my soul to you.
You, Lord, guided David to pen these words. But what do these words mean? You say throughs David’s tongue, “in sin.” You have used that phrase before through the lips of Moses. For, if a man did not fulfill his vow to you in the law, you proclaimed him “in sin” (Dt 23:21-22). Or if he payed not the wage of his workers, you labeled him “in sin” (Dt 24:15). Thus, he guilty for trespassing your law. But what else say you of the man who is in sin? Does he die for the sins of others or for his own sin?
Nay, not for others, oh Lord; but for his own. As you have said, “Fathers shall not be put to death because of their children, and children shall not be put to death because of their fathers; each one shall be put to death for his own sin” (Dt 24:16, LEB; cf. 2Kg 14:6, 2Ch 25:4). So, it is not for the sin of others that a man should be guilty. It is for his own sin. Even the Psalmist who speaks of guilt from his infancy claims his own guilt, saying, “For I know my transgressions, and my sin is ever before me. Against you, you alone, have I sinned, and done what is evil in your sight” (Ps 51:3–4, NRSV). His guilt in sin is caused by none other than himself, not by his ancestors. Thus, those who claim the embryo carries Adam’s guilt apply injustice to your word and do not understand your justice.
Oh Holy One, you are just and right!
You fill the heavens with your justice
As the sun burns in all his might.
As it rises, it shatters the night
Scattering the gloom of injustice.
Oh Yahweh, you are just and right!
Yet, I ask again, oh Lord, what does this passage mean? How does David say he was guilty from the womb? Can a new born sin without knowledge? Can a zygote lift its fist against you?  Shall we presume our understanding against your clear revelation? Nay, Lord. Each soul is guilty for his own sin. Yet, it is hard to understand how a zygote can sin against you.
When David cried thus, it was concerning his sin with Bathsheba. Did you declare him guilty of that sin before he was born? Did you thus cause this sin to be in his life? No, he speaks in the manner of most poets, especially those gripped in the torment of soul. He speaks in hyperbole, pointing to his nature that sin is ever present with him. His bent toward sin was ingrained in him from the moment of conception. And he might as well have been guilty from birth because his nature drew him to sin with Bathsheba. Oh Lord, it is his sin, not his father’s, that caused his guilt.
 I get this concept from the definition of the conceive (יָחַם) in the phrase “my mother conceived me.” It means to be hot, or conceive and as BDB puts it: “usually of sexual impulse of animals.” It is the moment when the sperm meets the egg and the zygote is formed.
 The title of the Psalm reads: Psalm 51:title (NRSV): “To the leader. A Psalm of David, when the prophet Nathan came to him, after he had gone in to Bathsheba.”
 Hyperbole best answers these challenges fitting the grand narrative better than Adamic guilt. And it is not out of place either. What W. G. E. Watson says about hyperbole describes this verse well: “Hyperbole is another word for ‘exaggeration’ with the additional implication that the poet is striving after vividness of imagery. . .. The main function of hyperbole, in fact, is to replace over-worked adjectives (such as ‘marvellous’, ‘enormous’, ‘colossal’) with a word or phrase which conveys the same meaning more effectively” (W. G. E. Watson, Classical Hebrew Poetry, pp. 316–321). In order to convey the enormity of his guilt over his sin with Bathsheba, he exaggerates how guilty he is all the way back to conception.
Some people may be dissatisfied with this explanation and accuse me of simply disregarding the truth because I don’t want to see it. I, however, disregard the eisegetical reading of original sin within this passage. I observe three issues with that understanding of this passage. First, nowhere in this Psalm, any of David’s Psalms, or any of the narratives concerning David is there ever a hint that Adam’s sin played a role in his theology. To find it implied here is tenuous at best. Second, the Psalm is dedicated to repentance of a particular sin (concerning Bathsheba). In the preceding verses he lays out his guilt concerning this sin and is quit clearly the actor. It seems tenuous, again, to read into a verse a confession of Adam’s guilt when he is quite adamant that it is his guilt on display in this passage. Third, and most importantly, you have to find a way around the Deuteronomistic concept of וּ֝בְחֵ֗טְא which is stated three times in Scriptures (cited above) to be the result of one’s personal sin and not the sin of one’s ancestors.