The standard of comparison provided by God is the Ten Commandments. Do you know them? Do you know where to even find them? Do you obey them? (Not one or two or most, but ALL them).
Why did God write down the Commandments, what's referred to generally as The Law written by the Hand of God in contrast to the Law of Moses written by the hand of Moses? (The Book of the Law, the Pentateuch, includes all the law, 613 commands in total.).
Mankind sinned before the law was written! That should come as no surprise, but I can hear them now "I didn't know that was wrong!" God gave the law so that man was without excuse! Right and wrong were no longer hidden in the mysteries of God, but set in stone!
Deuteronomy 30: 10 "If thou shalt hearken unto the voice of the Lord thy God, to keep his commandments and his statutes which are written in this book of the law, and if thou turn unto the Lord thy God with all thine heart, and with all thy soul. 11 For this commandment which I command thee this day, it is not hidden from thee, neither is it far off. 12 It is not in heaven, that thou shouldest say, Who shall go up for us to heaven, and bring it unto us, that we may hear it, and do it?13 Neither is it beyond the sea, that thou shouldest say, Who shall go over the sea for us, and bring it unto us, that we may hear it, and do it?"
Let's stop and look at two of the covenants (deals made by God for mankind). The Old Testament is about the covanent of "law", while the New Testament is a covanent of "grace". Some say that the Law no longer applies, but that by grace alone (sola gratia) that we're saved. Others say that we're saved by grace, but must keep the Law to obtain salvation, while others believe that the Law is the assurance of our salvation.
Regardless of your Calvinistic tendencies, all Christians should believe that Christ was our example and that we're called to be Christlike! There's much scripture to support that statement. Since Christ wasn't a sinner (law-breaker) and we're to be as much like Christ as humanly possible, then we are to do our best to keep the Law! However, much of the Law (that part written by Moses) is ceremonial. The part of the Law most important to God is the Decalogue. Hence, every Christian should strive to please God in this manner! There are rewards and punishments that go along with our compliance, usually how close we're able to commune with God!
Those who say "I've been good" are missing the "grace" part of the equation! No you're not good! If you say that you are, then you're deceived. Satan told you that you are "good" to keep you from seeking salvation! Romans tells us that "There is none good. No not one!" and this is reinforced by Jesus himself:
Matthew 19:16 "And, behold, one came and said unto him, Good Master, what good thing shall I do, that I may have eternal life? 17 And he said unto him, Why callest thou me good? there is none good but one, that is, God: but if thou wilt enter into life, keep the commandments. 18 He saith unto him, Which? Jesus said, Thou shalt do no murder, Thou shalt not commit adultery, Thou shalt not steal, Thou shalt not bear false witness, 19 Honour thy father and thy mother: and, Thou shalt love thy neighbour as thyself.
God only is good! However, verse 18-19 tell us what we're to do to have eternal life. We are to be good! What is "good". Obeying the Commandments! In fact the Greatest Commandment to love God and neighbor is a summary of the Decalogue!
Now since you know that in yourself you're not good enough to "save yourself" what does it take? You must be a disciple (follower) of Jesus! You believe in him, you're sorry that you disrespected him out of disobedience to the Law, you accept him and that he died for you, you believe that he is risen and yet lives! That''s all it takes! By this simple thought (sacrifice of self) you're saved! Nothing beyond simple faith (self-sacrifice) qualifies you for eternal life. It's a gift God has given you; Christ shed his own blood and died so that you may have eternal life... which, by the way, you don't deserve.
If you look at the "repentance" part, if you believe that you're "good" what have you to confess to God that you did wrong? I bet that not only have you broken one commandment, but you have actively or in your heart broken them all! Have you wished someone dead? If so, you're a murderer! Have you desire for what someone else has? Then you've coveted! Have you lied or avoided truth? Then you're a liar! Have you disrespected God? Then you're a blasphemer! Have you placed other things above God? Then you're an idolater! Have you sassed your parents? Then you have disrespected them! You see, we're all "scum". We're blaspheming, lying, lusting, disrespectful idolaters; yet we think we've been "good". That's what Satan wants you to think, because without remorse for sinning there is no salvation!
Maybe you're naive to your own sinful life. Perhaps you try never to disobey. I bet that everybody has broken all the Commandments, but let's give you the benefit of the doubt! Perhaps you've broken only one:
For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all.
If you've sassed your parents you're just as lost as the rest of us! By breaking one Commandment you are a sinner just like the rest of us! (While you're thinking about how good you are by only breaking one, consider that you just may be propping yourself up as an idol, for pride is why we all face death!)
Should we try to be "good"? Most certainly... but it won't save us! How will we know if we really love Jesus enough to merit everlasting life? It's by keeping his Commandments!
1 John 2:3 "And hereby we do know that we know him, if we keep his commandments. 4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. 5 But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.6 He that saith he abideth in him ought himself also so to walk, even as he walked."
We are to walk as Christ walked. That's sinless. Will we ever be sinless? Fat chance! However, we can desire to please God and our self-control shows respect for God; and remember that Jesus IS God. Too many Christians fail to place an emphasis on holy living. If you truly have accepted Jesus then you will be "good". Because we're saved doesn't mean that we no longer have to keep the Law. We should be joyous that we now love the Law!
No, being "good" is not enough! That's pride! Jesus called those who thought they were "good" vipers! That means if you perceive yourself as "good", you're a snake! That's just not good!
It would be better if you are honest about your degenerate life than claim righteousness. In God's eyes if you are just a "good" person, you're despicable. Why, because you have failed to accept the grace that his vicarious death provided. Start now, this instant, examine yourself honestly; are you really "good"? The obvious and only answer is "No you're not!". What then, do you need to do? Accept the gift that has already been made for you. Accept Jesus' atonement!
Romans 5:8 "But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us."
Did Christ die for the "good"? No, he died for the sinner. That's all of us. Your self-deification that you are "good" as God was good; is blasphemy. That's the only one sin that God won't forgive:
Matthew 12:31 "Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.
The Holy Ghost has the ultimate grace. He calls the sinner to redemption. If you fail to respond. that's blasphemy! You rejected Christ as Savior. That sin and that sin alone shall keep you from eternal life. Why should Jesus allow you to live with him in heaven if you don't even believe in him?