In Luke 18:9-14, we find my favorite parable in the entire Bible. It is my opinion that every church should make an effort to teach it, preferably once a month, as it tackles one of the biggest problems in the Church today: Pride. Here is what it says:
"And he spake this parable unto certain which trusted in themselves that they were righteous, and despised others: Two men went up into the temple to pray; the one a Pharisee, and the other a publican. The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican. I fast twice in the week, I give tithes of all that I possess. And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner. I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted."
So what we see here is two distinct people. Both men are sinners, but only one of them recognises it. The Pharisee sets himself apart from other men, boasting not only that he is unlike them, but also that he is better than them. While trumpeting his good works, he looks down on other men, even the tax collector who stood in the same room.
The tax collector, by contrast, doesn't even lift his head. Recognising his own sin, he is clearly grieved, and without referencing a single other person, without mentioning even one of his good deeds, and without making a single excuse, his one request is "Lord, have mercy on me, a sinner".
This parable, I believe, not only teaches us humility in the heart, but also in the doctrine. As Christ Himself states, it was the tax collector, not the Pharisee, who was justified by God. Why? Because he asked for mercy.
Although there are a wide variety of views on salvation in the world today, there really are only two: By grace through faith, or by works. Almost no nominally Christian tradition claims one is saved exclusively by works. Even those with a heavy emphasis on works will at least admit faith is necessary. However, scripture makes it abundantly clear that aside from faith being the sole requirement for salvation, with works being produced as a result (Ephesians 2:8-10), it also clearly tells us that when you add works into the mix, "grace is no longer grace" (Romans 11:6).
Thus, when the tax collector asks for mercy, what he's actually saying is "God, I know I don't deserve salvation, but I believe you are kind enough to give it to me anyway". This is the Christian position. Christ did not die to atone for sins we can atone for ourselves, He became sin who knew no sin that we might become the righteousness of God in Him (2 Corinthians 5:21). In other words, the only works involved in our salvation are our evil works that made it necessary, and His good works that made it assured. All we need do is claim it by faith.
Contrast this with the tax collector. When he boasted of his own goodness, he actually disgraced the cross. It is, first of all, very offensive to suggest that the self sacrificial death of the one and only Son of God wasn't enough, and that He somehow needs you to help Him save you. But along with this blasphemy, if the Pharisee expects God to judge his works, why should God only judge the good works?
During His ministry, Jesus had some very strong words with the Pharisees. While they certainly boasted of their righteousness, they had added a lot of traditions to the word of God, and diminished a lot from it. They would often find "clever" ways to circumvent the law, if not flat out disobey it. In his boasting, the Pharisee in the parable, who was representative of most Pharisees, ignored all the things in his life that made him just as unworthy of God as the tax collector. Thus, he, too, should have bowed his head in shame, not approaching the altar, but instead standing off afar and praying "Lord, have mercy on me, a sinner".
To figure out if you have the right view of salvation, simply ask which man are you encouraged to be like? Those who follow works-based "gospels" are ultimately like the Pharisee. They trust in their own works, which produces only two attitudes: 1. I'm so bad not even the cross can save me, or 2. I'm so good, I hardly need it to. But scripture indicates that if you ask God to judge you by your works, He will. And since our works are what gave us need of salvation in the first place, that will not go down well for us.
By contrast, those who believe "...by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast" will find a very warm-hearted God, who looks upon us as beloved children, because we did not trust in our own filthy righteousness (Isaiah 64:6), but in His.
If your view on salvation is correct, you will inevitably become like the tax collector. Your sin will grieve you to your very core, and you will doubt (correctly) that you are worthy to even approach God. Nevertheless, though you are unworthy of Him, you will recognise that He is worthy of you, and He is rich in love and mercy. Therefore, you will approach Him anyway, seeking His mercy, and going down to your house justified.