Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need. Hebrews 4:16
Apostle Paul calls the believers "saints" which means "sanctified ones.”
Unto the church of God which is at Corinth, to them that are sanctified in Christ Jesus, called to be saints, with all that in every place call upon the name of Jesus Christ our Lord, both their's and our's: (I Corinthians 1:2)
Yet in the same letter he corrects these "saints" because of sin. They were believers and sanctified in Christ, but some of them were not living right in their daily conduct as is pleasing unto God. These believers had started the process but had not moved on to perfection in Christ.
Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; (Hebrews 6:1)
They were forgiven of their sins through redemption from dead works. These sins were forgiven once and for all.
For by one offering he hath perfected for ever them that are sanctified. (Hebrews 10:14)
This initial perfection was received at the time they were renewed by water and spirit and accepted Jesus as Savior. But these Christians had not gone on to perfection or spiritual maturity. They had not continued to put off the "old man" of sin:
Knowing this, that our old man is crucified with Him, that the body of sin might be destroyed, that henceforth we should not serve sin. (Romans 6:6)
What shall we say then? Shall we continue in sin, that grace may abound? God forbid. How shall we that are dead to sin, live any longer therein? Therefore...we also should walk in newness of life. (Romans 6:1,2,4)
After salvation, you are to live a new life in Christ:
Not as though I had already attained, either were already perfect; but I follow after, if that I may apprehend that for which also I am apprehended of Christ Jesus. (Philippians 3:12)
And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness. But if the Spirit of Him that raised up Jesus from the dead dwell in you, He
that raised up Christ from the dead shall also quicken your mortal bodies by His spirit that dwelleth in you.
...but if ye through the Spirit do mortify the deeds of the body, ye shall live. (Romans 8:10,11,13)
The beautiful thing about God is that He does not leave us comfortless but provides an avenue in which we can call upon Him in our distress:
When the flesh results in you doing those things we would not, God has provided a way to restore you to perfection.
For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death. 2 Corinthians 7:10
For if we confess our sins, He is faithful and just to forgive our sins and to cleanse us from all unrighteousness. (I John 1:9)
. . . Greater is He that is within you than he that is in the world. (I John 4:4)