It is impossible for any of us to achieve holiness in God's sight by our own strength or willpower. We must come to Him saying, "Lord, I have nothing to give You. You have to do it all."
Yet we remain convinced, "If I could just get victory over this one last, remaining sin, I'd be able to live holy." So we take in hand the sword of willpower, promises, and good intentions and set out to kill the enemy in our hearts. But we can never be holy while standing on the ground of self-righteousness.
You and I face the same burning bush Moses did. And that bush is a type of God's fiery zeal against all flesh brought into His presence masquerading as holiness. He says to us, "You cannot stand before Me on that kind of fleshly ground. There is only one holy ground and that is faith in My Son and His work on the cross."
This is the only way God ever could have saved and reconciled a whole world. If our works merited our salvation, only a select number would be candidates for salvation—but I believe Christ died for all.
We can behold the worst thief, rapist, murderer, drug addict or alcoholic—people who have no good works at all—and testify, "By repentance and faith, they can be presented righteous in Christ Jesus."
That is the true, saving power of God. Yet many Christians live as if their works are sufficient. On judgment day, they will stand before God in their flesh, saying, "Look at everything I've done for you, Lord. I've worked to stay clean and holy. I've prophesied, fed the poor, healed the sick, cast out demons. And I've done it all to please You!"
But God will answer, "You did none of those things through the power of My Spirit. You did them all in your own strength. I accept the righteousness of only one Man—My Son. And I do not see My Son in you."
"Of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption: that, according as it is written, He that glorieth, let him glory in the Lord" (1 Corinthians 1:30-31).