A man is saved only by grace—only by grace! (See Eph. 2:5 and 2:8.) Faith is the instrument or vessel, and works are the evidences that prove, perfect, and complete that faith. (See James 2:22.)
"... (by grace you have been saved)," Ephesians 2:5
"For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, that no one should boast." Ephesians 2:8-9
"For by grace you have been saved." Through what? "Through faith." What is not of ourselves? "Faith." Why? "It is the gift of God." Why is it a gift of God? "That no one should boast." If you are saved by your faith, you can boast in your faith, which makes your faith "a result of works." Something you did. Something you look to in order to obtain salvation. Faith in your faith. You can say, "Look how great my faith is! My faith saved me!" No! God saved you! And for nothing you have done or will do, and for nothing in and of yourself. He saved you for His glory.
"But we believe that we are saved through the grace of the Lord Jesus, in the same way as they also are." Acts 15:11
Salvation is not the result of works. Anything you look to (other than Christ Jesus Himself) in order to obtain salvation will land you in Hell. Faith and works (works of the Law or good deeds) can be things you look to. Anything you do in order to obtain salvation will land you in Hell. Faith and works (works of the Law or good deeds) can be things you do.
Faith and repentance are both gifts from God. You cannot exercise faith unless God has granted faith to you, and you cannot exercise repentance unless God has granted repentance to you. If God grants you one, He will also grant you the other. In order to believe and repent, you would have to change from unregenerate to regenerate, you would have to change your heart of stone to a heart of flesh, you would have to change yourself from being dead in trespasses and sins to being spiritually alive; none of which you can do yourself! Once those changes have taken place by God's grace, you cannot reverse them. God saves us entirely or we are not saved at all!
"You do not believe, because you are not of My sheep." John 10:26