God is trustworthy — He saved us and indwells us by His Spirit of holiness, despite Him already knowing every sin that we'd ever commit as Christians. All of our indifferent disobedience to Him and self-centered backsliding, for truly, without question, each one of us, in our fleshly nature, are capable of grievous evil. Though, consider this: Humanity's horrendous wickedness didn't keep God away from us, but rather, it led Him to graciously send His own Beloved Son for our eternal benefit (Romans 5:8); to ransom us from all lawlessness by the perfect sacrifice of Jesus Christ (Titus 2:14). For this reason, please don't believe the lie of Satan, that God will give up on you, or forsake you as His child!
Nonetheless, our (experiential) holiness is very important to God (1 Peter 1:15-16), but we cannot share in His, if we conceal our transgressions from Him (Proverbs 28:13). Therefore, we're called to pour out our hearts before Him because He is worthy of our trust (Psalm 62:8) — praying humbly in all transparency, because He knows already the content of them. For God is a refuge for His children; He helps the weak, broken and discouraged, and rewards all who diligently and sincerely seek Him (Hebrews 11:6)
"For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin. Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need." (Hebrews 4:15-16)