Because no matter how little wrong we do with our hands, the best people know we have to fight against ourselves.
If we let ourselves, there is no evil we would not do. Resisting our evil does not mean it isn’t there. Refusing to admit our evil is evil. We cannot pay for this evil in us: there is nothing extra we can do to make up for it. We have already failed to be good, and there is nothing better than being good, there is nothing that can be offered in its place.
It is by God’s mercy that we are forgiven, and even rewarded for the good we do. He gives his mercy to all who do his will, and reject their evil.
He that hideth his sins, shall not prosper: but he that confesseth, and forsaketh them, shall have mercy.The Proverbs of Solomon, 28:13
God resisteth the proud, and giveth grace to the humble.The Letter of James, 4:6
If we forsake our sins, he will give us his mercy. But if we think that doing good can make up for sin, or make us worthy to escape punishment, this is pride.
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.The Prophecies of Ezekiel, 33:13
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.The Gospel of Luke, 18:11-14
If we think doing good is something extra, then we have not confessed the sinfulness of our sin. We owe God everything, doing everything is the least we can do; it doesn’t make a profit. To sin is to do less than nothing, and is unthinkable.
When ye have done all those things, which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.The Gospel of Luke, 17:10
So it is when we walk humbly with God, do the will of the Father, and love him and his laws, that he will give us his mercy.
Know therefore that the LORD thy God, he is God, the faithful God, which keepeth covenant and mercy with them that love him and keep his commandments to a thousand generations;The Fifth Book of Moses, 7:9
For much of history few realised what the mercy of God cost for God to give it to us. But two thousand years ago in Israel God showed what his mercy means, what it costs him.
God became a man named Joshua (or “Jesus”), and allowed himself to be killed in a torturous Roman execution. Then he returned to life to put away the condemnation of eternal death for anyone who ever has or ever will trust in God’s mercy.
Now, after he has revealed this to humanity, those who know this have a far greater responsibility even than before. If we turn away from God who not only created us but died for us, we have less than no excuse.
And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people, saying with a loud voice,
Fear God, and give glory to him; for the hour of his judgement is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters.The Revelation to John, 14:6-7