In v. 2 the metaphor shifts a bit as if he is a man thrown down into a well. He sinks into the deep mire "where there is no standing." In other words, now we are to imagine him thrown into such a slimy pit that he cannot touch the bottom. "I have come into the deep waters, where the floods overflow me" (v. 2). In v. 3 we learn that the tears of the sufferer have added to the flood. He has cried so much that he is dehydrated and his throat is parched.
What this psalm remind us is that Jesus came to save men from such a hopeless state of despair. We cannot touch the bottom of our sin. Even the best of men are capable of the worst of things.
Anselm of Canterbury in the eleventh century said, "You have not yet considered the weight of sin."
John Calvin said among other things that "according to the constitution of our nature, oil might be extracted from a stone sooner than we could perform good works." In another place, Calvin said that no man knows even as much as 1% of his sin.
David Martyn Lloyd-Jones said: "When a man truly sees himself, he knows that nobody can ever say anything about him that is bad."
Joel Beeke said that "we are active ‘sin-aholics’ by nature."
Jesus did not come to merely stand on the sideline and casually toss us a life preserver. No, he jumped into our experience alongside of us. The Word became flesh and dwelt among us (John 1:14).
He did not come to be a sinner but to be tempted in all points even as we are. He came to be despised by sinful men. This is our condemnation that the light was in the world but men loved darkness rather than light because their deeds were evil (John 3:19). His enemies were more than the hairs on his head (v. 4). His enemies were a countless throng. They number every single human being who has ever lived. Apart from God changing our hearts we do not love Christ. Still, he came to enter fully into our experience and to be among us for the glory of God.