Imagine a slanted field of snow, where the snow has drifted largely down toward the bottom of the field. The further one moves up the field, the less snow he or she encounters on the ground. The top of the field has no snow on it at all.
Now, imagine two children, each with equal sized snowballs of their own making. One snowball is not smaller or larger than the other. However, as one child moves further down the field, his snowball gets larger and larger. He himself is eventually engulfed in the snow. The other child, moving in the opposite direction up the field, accumulates less snow, and in fact, begins to lose some snow off of his snowball as it sticks to the barren ground. Eventually, his snowball is reduced to nothing when he arrives at the top of the field.
This illustration is one where we see that both individuals are equal in terms of the size of their snowballs, but not the same in terms of their movement, which in turn will determine the destiny of their creations. One is working toward the building of his snowball and to be engulfed in it, and the other is working to decrease his snowball and eventually rid himself of it altogether.
Now, let's pursue a common religious myth we hear echoed throughout our culture: "We're all sinners. We all make mistakes. Nobody's perfect." All of these statements are true in and of themselves, that is, if we take only what is explicitly said outside of the context that implies something quite different from the truth. When understood in the context of self-rationalization and justification of sin, they are false statements, precisely, because they mean to assert the claim that all sinners are both equal in terms of the amount of sin they have and are therefore going in the same direction. In other words, we may all be sinners, but we are not all the same kinds of sinners. In fact, there are two kinds of sinners.
One sinner is moving further into sin. He seeks to justify why it's not really a sin for him personally or why it's not a sin at all. He seeks to justify that even if it is a sin, everyone else is also a sinner, and so there is no reason he should seek to rid himself of it. He is moving downhill, accumulating for himself more reasons why he is justified in his decisions to live in sin. He is entrenching himself by saying he is no different than everyone else, and will eventually be completely engulfed by his sin once he reaches his final destination.
The other sinner doesn't want to be a sinner. He wants to decrease it in his life. In fact, he wants to rid himself of it. His sin, in terms of the grossness and the amount of it, does not seem to be any lesser than any other sinner's; yet, when he sins, he seeks forgiveness through repentance. This man's trajectory is set toward God and he uses even the occasions where he sins to pursue a relationship with God. Hence, as he does so, his sin lessens, and eventually is wiped away completely when he reaches his final destination.
You see, there are sinners and there are sinners. One sinner is an unrepentant sinner. He wants his sin. It gives him comfort. It gives him purpose. It gives him pleasure. He doesn't want to rid himself of it, so he uses the excuse that everyone else is a sinner too in order to protect that which he does not wish to lose out on in his life. The other sinner is a repentant sinner. He hates his sin. He realizes it is slavery and he is always seeking to be free of it by pursuing the presence of Christ, even when he fails. When he is dirty, he seeks to become clean. He does not use the fact that others are sinners as an excuse for his own sin. Instead, though the whole world were to be permitted by God to be entrenched in sin, he wishes to be rid of it anyway. For the repentant sinner, the goal is to love God by seeking to become what God has granted him in Christ Jesus. For the unrepentant sinner, however, his goal is to run away from what he could be in Christ, because he knows that in pursuing Christ, he would lose the sin that gives him the life that he loves.
So we are all sinners. We all make mistakes (although mistakes and sins are two completely different things). Nobody is perfect, save God alone. But we are not all the same kinds of sinners. Saved sinners long to be saved from sin completely. Unsaved sinners long to be rid of the voice that calls them to repent, but they wish to keep their sin. This is especially true when we begin to understand that sin is doing what we want to do in contrast to what God wants us to do in any given situation. The unsaved sinner doesn't even want God to define sin this way, as it doesn't allow him to excuse himself by viewing sin as any evil act that is much worse than anything he might do.
We may both be sinners. We may both be on the same path of life. But some are going one way on that path, moving further and further away from a self-worshiping life and others are moving more and more into it. As such, all are sinners, but not all sinners are the same.
For the Christian, God has predestined us from before the foundation of the world to become holy and blameless, and it is in pursuing this vision God has for us that we prove our sinful lives to be moving in a different direction than those who wish to bury themselves in their own vices. As Ephesians 1:6 says, we desire this because of what God has done for us in predestining us for this purpose "to the praise of His glory." This is God's work, lest we ever come to think that although we are sinners, we are better sinners than others because of something within us. It is God drawing us ever to Himself that calls us up the hill, to turn away from moving down the field and begin to move up it toward Him.
Our sins are just as black as the sins of others, but the movement of our lives works against them. They become the vehicles through which we remember our hopelessness without Christ, as we call out for Him in their torment of us; and thus, even our sins become the catalyst for our sanctification from them. But it is not so for the unrepentant sinner whose Christless life is geared toward self. He drinks up sin like water, never seeking to purge it from himself.
Hence, all of humanity is in sin, but true humanity and false humanity are not going in the same direction with their sin, one toward life and one toward death. As such, we should be looking more at the direction we are moving than at the equal size of our snowballs.
But evil men and impostors will proceed [from bad] to worse , deceiving and being deceived. You, however, continue in the things you have learned and become convinced of, knowing from whom you have learned [them], and that from childhood you have known the sacred Scriptures which are able to give you the wisdom that leads to salvation through faith which is in Christ Jesus. (2 Tim 3:13-15)
Therefore, since we have so great a cloud of witnesses surrounding us, let us also lay aside every encumbrance and the sin which so easily entangles us, and let us run with endurance the race that is set before us, fixing our eyes on Jesus, the author and perfecter of faith, who for the joy set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God. (Heb 12:1-2)
If we say that we have fellowship with Him and [yet] walk in the darkness, we lie and do not practice the truth; but if we walk in the Light as He Himself is in the Light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin. If we say that we have no sin , we are deceiving ourselves and the truth is not in us. If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness. If we say that we have not sinned, we make Him a liar and His word is not in us. (1 John 1:6-10).