Salvation Is Not By Works
For 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. (Ephesians 2:8-9)
You Can't Work Your Way To Heaven
Since the fall, all of mankind has been enslaved to sin. When Adam and Eve sewed fig leaves together to cover their nakedness, it was not accepted by the LORD, who instead gave them coats of skins to establish that blood sacrifice was the only acceptable payment for sin. This basic truth has been the crux of conflict between the Elect and the Reprobate from the beginning. Cain killed Abel his brother because God would not accept the work of his hands as a sacrifice, but rather accepted Abel's sacrifice of blood that followed the pattern the LORD put in place.
We are conceived in sin, being created in the image of fallen Adam, and are therefore incapable of supplying the innocent blood required to pay for sin. In addition to that, we are incapable of living in perfect subjection to the Law of God which only adds to our insurmountable debt to Him, and if you offend in one point of the law you are guilty of the whole law. Therefore, if we are at all dependent on our works to bring us salvation, we would be found wanting - condemned by the law.
Salvation is only attainable through grace, which is a gift of God, that no man should boast of his works. Grace, not the law, is what has dominion over the Elect. Only those to whom grace is given will be drawn to Christ, have faith in Him, and be saved.
Good Works Are The Result (Not The Cause) Of Salvation
That is not to say that works have no value, or that obedience to the law is optional. A Christian shows his faith by his works - striving to live in obedience to the moral law of God in every aspect. Being a hearer and a doer of the word. Though works cannot grant you salvation, they are evidence of the hope that resides in you, and they are the fruit that exhibits who you are servant to - sin or God. Those who serve God in word only will not be granted entrance into the kingdom of heaven. True Christians will do everything to mortify sin in their members, their faith driving their works, knowing that "the wages of sin is death, but the gift of God is eternal life through Jesus Christ our Lord." (Romans 6:23).
Bible Support
Genesis 3:21 - "Unto Adam also and to his wife did the LORD God make coats of skins, and clothed them."
Genesis 4:3-5 - "And in process of time it came to pass, that Cain brought of the fruit of the ground an offering unto the LORD. And Abel, he also brought of the firstlings of his flock and of the fat thereof. And the LORD had respect unto Abel and to his offering: But unto Cain and to his offering he had not respect. And Cain was very wroth, and his countenance fell."
James 2:10 - "For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all."
Romans 3:20,23 - "Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin...For all have sinned, and come short of the glory of God."
James 2:17-18 - "Even so faith, if it hath not works, is dead, being alone. Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works."
Romans 6:15-23 - "What then? shall we sin, because we are not under the law, but under grace? God forbid. Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness? But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you. Being then made free from sin, ye became the servants of righteousness. I speak after the manner of men because of the infirmity of your flesh: for as ye have yielded your members servants to uncleanness and to iniquity unto iniquity; even so now yield your members servants to righteousness unto holiness. For when ye were the servants of sin, ye were free from righteousness. What fruit had ye then in those things whereof ye are now ashamed? for the end of those things is death. But now being made free from sin, and become servants to God, ye have your fruit unto holiness, and the end everlasting life. For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord."
Titus 3:5 - "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."
Matthew 7:21 - "Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven."
James 1:22-25 - "But be ye doers of the word, and not hearers only, deceiving your own selves. For if any be a hearer of the word, and not a doer, he is like unto a man beholding his natural face in a glass: For he beholdeth himself, and goeth his way, and straightway forgetteth what manner of man he was. But whoso looketh into the perfect law of liberty, and continueth therein, he being not a forgetful hearer, but a doer of the work, this man shall be blessed in his deed."