We read here that the gravity of our sinful nature as human beings is much deeper than we often realize. Not only are we sinful, but in our fallen condition we are incapable of doing anything good in His sight. The apostle Paul — formerly a Pharisee — describes our throats as open graves, our tongues as filled with the venom of serpents, and our feet as swift to shed blood like that of a murderer.
The point is simple: from head to toe, surface to core, our lives are thoroughly contaminated by sin. Like a bottle of water tainted by a single drop of red dye, so too our lives become—completely permeated and stained. The dye spreads through the entire bottle, leaving no part untouched. That is a picture of our spiritual condition.
Worse yet, the things Paul lists are elements that, under Jewish ceremonial law, would render a person unclean. In effect, he is declaring that we, as human beings, are unclean because of our sin.
So the question is this: What does a holy, just, and righteous God do with sinners like us — completely stained by sin and living in active rebellion against Him? As the righteous Judge, He is obligated to condemn sinners. Like those declared unclean under the Old Testament law, we are cut off from the presence of God because of our sin, left with nothing but a guilty verdict and a swiftly approaching day of judgment.
Only when you understand both the nature of God and the nature of humanity can you truly grasp the Gospel — the good news of Jesus Christ.