HE BIBLE tells us that, all men are sinners and that not even our most righteous works can get us into heaven.

6 But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.

Isaiah 64:6

17 For the law was given by Moses, but grace and truth came by Jesus Christ.

John 1:17

10 As it is written, There is none righteous, no, not one:

Rom. 3:10

22 For though thou wash thee with nitre, and take thee much soap, yet thine iniquity is marked before Me, saith the Lord GOD.

Jer. 2:22

9 By Moses came the law, which no man can live up to:

10 For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all.

James 2:9-10

12 Therefore, thou son of man, say unto the children of thy people, The righteousness of the righteous shall not deliver him in the day of his transgression: as for the wickedness of the wicked, he shall not fall thereby in the day that he turneth from his wickedness; neither shall the righteous be able to live for his righteousness in the day that he sinneth.

13 When I shall say to the righteous, that he shall surely live; if he trust to his own righteousness, and commit iniquity, all his righteousnesses shall not be remembered; but for his iniquity that he hath committed, he shall die for it.

14 Again, when I say unto the wicked, Thou shalt surely die; if he turn from his sin, and do that which is lawful and right;

15 If the wicked restore the pledge, give again that he had robbed, walk in the statutes of life, without committing iniquity; he shall surely live, he shall not die.

16 None of his sins that he hath committed shall be mentioned unto him: he hath done that which is lawful and right; he shall surely live.

17 Yet the children of thy people say, The way of the Lord is not equal: but as for them, their way is not equal.

18 When the righteous turneth from his righteousness, and committeth iniquity, he shall even die thereby.

19 But if the wicked turn from his wickedness, and do that which is lawful and right, he shall live thereby.

Eze. 33:12-19

2 For if Abraham were justified by works, he hath whereof to glory; but not before God.

3 For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness.

4 Now to him that worketh is the reward not reckoned of grace, but of debt.

5 But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.

6 Even as David also describeth the blessedness of the man, unto whom God imputeth righteousness without works,

7 Saying, Blessed are they whose iniquities are forgiven, and whose sins are covered.

8 Blessed is the man to whom the Lord will not impute sin.

Rom. 4:2-8

For which reason, man is condemned to death and damnation.  And for which reason man cannot earn his own righteousness and salvation.  

4 Not by works of righteousness which we have done, but according to His mercy He saved us, by the washing of regeneration, and renewing of the Holy Ghost;

Titus 3:5

8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:

9 Not of works, lest any man should boast.

Eph. 2:8,9

For this reason Jesus had to die.  Because He Was sinless His death did not have to pay for his own sins; He could pay for the sins of others, and in that way earn our salvation.

And if there was any other way for man to be saved God would surely not have sent His Own Son!  

21 I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.

Gal. 2:21

6 For when we were yet without strength, in due time Christ died for the ungodly.

7 For scarcely for a righteous man will one die: yet peradventure for a good man some would even dare to die.

8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us.

9 Much more then, being now justified by his blood, we shall be saved from wrath through him.

Rom. 5:6-9

As a result, if we are trusting, ever so slightly, in our own righteousness or good works to get us into heaven, we will always be prone to doubting our salvation.  Assurance comes from putting our total reliance in God… for all our salvation!

9 And He spake this parable unto certain which trusted in themselves that they were righteous, and despised others:

10 Two men went up into the temple to pray; the one a Pharisee, and the other a publican.

11 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.

12 I fast twice in the week, I give tithes of all that I possess.

13 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.

14 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.

Lu. 18:10-14