Wuithout denying that it is through grace alone that we are sanctified, consider
[12] Wherefore Jesus also, that he might sanctify the people by his own blood, suffered without the gate. [13] Let us go forth therefore to him without the camp, bearing his reproach. [14] For we have not here a lasting city, but we seek one that is to come. [15] By him therefore let us offer the sacrifice of praise always to God, that is to say, the fruit of lips confessing to his name. [16] And do not forget to do good, and to impart; for by such sacrifices God's favour is obtained.[...]
[20] And may the God of peace, who brought again from the dead the great pastor of the sheep, our Lord Jesus Christ, in the blood of the everlasting testament, [21] Fit you in all goodness, that you may do his will; doing in you that which is well pleasing in his sight, through Jesus Christ, to whom is glory for ever and ever. Amen (Hebrews 10)
Quite simply, since you are judged by your works (Matthew 25) you cannot be holy without them.
Matthew 7:21- 23 "Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. On that day many will say to me, 'Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?' And then will I declare to them, 'I never knew you; depart from me, you workers of lawlessness.'
Here are people who believed in God and did mighty works(miracles), cast out demons, and prophesied in Jesus name. They had the works and they believed God.
And yet Jesus said that He never knew them. What were they missing?
It simply goes to show that you CAN'T depend on works. They did and they appealed to them and yet their works clearly didn't save them or in any way contribute to their salvation.
I am sorry, but I get the impression that the word "holy" has been used so frequently and so inappropriately that it has lost its real meaning. Holy means sanctified, set apart, consecrated, sacred, dedicated, devoted to and hallowed. God is Holy and only he can make us holy (Lev. 20:8). The righteousness that he requires for us to dwell with him for eternity is not something we can ever merit or earn but is imputed to us by his grace through faith. Our good works are a testament to others of the new nature that has been born within us and it comes from his very own spirit. These works do not cause the sanctification or holiness they are proof of his working within us. The blood of Christ alone sanctifies us, makes us holy in his sight.
On the contrary, we can't be holy WITH them. All our righteousness is as filthy rags in God's sight.
Matthew 5:20 For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven.
Our works will NEVER qualify us for heaven. That's why Christ had to die, so that His works could be credited to our account and we'd be the righteousness of God in Christ.