Sin is often subtle. Satan cloaks it in many ways, often through feelings of shame and guilt, leading us back into sin and hence, sinning against God.
~Lisa Blair

How can this be so? All sin is sin against God. Yes, He freed us of sin that strangled us when Jesus suffered on the Cross and gave His life for us. We are no longer bound by our sins. We received salvation because Jesus died for our sins. Our Father promised us that He would give us redemptive life.
Therefore, since we have a great high priest who has ascended into heaven, Jesus the Son of God, let us hold firmly to the faith we profess. Hebrews 4:14 NIV
As humans, we will sin until Jesus returns and conquers Satan, but through redemption, we do not have to wear it like an albatross. It does not have to hang around our necks, carrying it with us into eternity. We have been given the gift of repentance. When we acknowledge our sin, we have the opportunity to ask God’s forgiveness. When we do so, He forgives us and removes the sin from our lives as far as the east is from the west.
8 The Lord is compassionate and merciful, slow to get angry and filled with unfailing love 9 He will not constantly accuse us, nor remain angry forever. 10 He does not punish us for all our sins; he does not deal harshly with us, as we deserve. 11 For his unfailing love toward those who fear him is as great as the height of the heavens above the earth. 12 He has removed our sins as far from us as the east is from the west. Psalm 103:8-12 NLT
It is our faith that is affected when we ask for forgiveness only through guilt to relive the sin again and again in our minds. If God forgave us, removed the sin from us, we must do the same. If we don’t, we are sinning against God. We are doubting His Word and resigning ourselves to the prison (faithlessness) Satan creates to incarcerate us within the walls of our past.

Most of us have done things we are ashamed of doing. Things that, if given an opportunity, we might have done differently, but we cannot change the fact that it occurred. We can accept God’s forgiveness and attempt to refrain from committing the same sin again. We may also find that there are consequences for what we have done, but the most important thing is that we learn from what we have done, repent and thank God that we are not bound by it any longer; until we forgive and place it in the sea of forgetfulness, we are sinning against God.
God warned those (of the Jewish faith) who became the first Christians about returning to their old ways in the Book of Hebrews. This warning is the same today as it was in the past. Returning to our old ways is an intentional act of denial. We deny God’s love for us and promise to keep us and never leave us, we reject His promise of redemption. We speak repentance but continue to carry the chain, we sin against our Father simply by denying His forgiveness.
If you are like me, and most humans, we have to work on forgiving ourselves once God has forgiven us earnestly. We have to learn to stop returning to the mental scene of the crime so to speak, thank God and move forward.
Moving forward is an act of maturity. As we learn about God’s promises, we must use them to reinforce who we are in Christ. This is an ongoing exercise. Living a Godly life is a process. Paul equates life as a race and crossing the finish line occurs when we perish from this earth and take up residence in heaven with Christ.
Warnings are opportunities to change. We are warned before we continue to repeat our past. God promised we are freed from sin when we repent. Repent and do not return to the past; do not bind yourself in regret and guilt. You have been freed. Accept it and move forward. Our Lord placed our sin into the sea of forgetfulness, and we must do the same. Let God set you on level ground. God’s Will is to free us from sin.

Teach me to do your will, for you are my God; may your good Spirit lead me to level ground. Psalms 143:10 NIV
Lord place me on solid ground, the land of uprightness (NKJV), lead me forward on a firm footing (NLT), lead me to level ground (NIV).
Failing to follow our Lord in our innermost being is living an outward life of a Christian. An outward life is one of self-righteousness and only a substitution for true faith. Releasing guilt must be an inner act of spiritual life in Christ that leads to Christian maturity. Holding on to guilt and shame is an act of spiritual immaturity, reflecting that we do not actually rely on Jesus Christ for salvation. Our sins are not unpardonable as was the case in the Old Testament. Christ provides the way for each of us who obey the gospel commands (by faith) to do so.
True repentance is complete surrender and submission to Christ and involves a change of mind and will to recognize and refuse our sin natures control over us and follow Christ. We must refuse to mentally return to the sin we committed, scolding ourselves over and over again. The Lord freed us from sin, accepted our repentance, and encourages us to move forward into Christian maturity. We should not sin against God. People who know what the gospel is about and refuse to repent and believe, in effect, crucify Christ all over again.
Believing the gospel through faith is an act. We have to intentionally hold fast to our faith, release the thoughts (guilt) that bind us, stop crucifying Christ over-and-over again, and move forward as maturing Christians.
Scriptures—biblegateway.com; Bible.com
Resources—BibleHub.com; GotQuestions.org; BFS. Lesson-Hebrews
Images—Google Images; PicMonkey