Our God is actually a very forgiving God. Scripture tells us that when we repent from sin He is ready and willing to forgive us (Psalms 86:5, Psalms 130:4). However, it is important to realize that repentance is required in order to obtain that forgiveness (Isaiah 55:6-7, Luke 13:3-5, Luke 15:7, 1 John 1:9). And, in His great love, when God forgives a sin He doesn't keep it in memory to use against you later; His forgiveness erases the sin from memory as though it never happened (Jeremiah 31:34). It is perfectly acceptable for us to pray for His forgiveness (Matthew 6:9-12, James 5:15).
OUR MEANS OF FORGIVENESS
According to Scripture the forgiveness of sin can only be accomplished through the outlet of blood (Hebrews 9:22) This is why our means of forgiveness from sin comes through Christ's spilled blood (Matthew 26:27-28, Luke 24:47, Acts 5:31, Acts 10:43, Romans 3:25, Ephesians 1:7). Before Christ shed His blood forgiveness was given through the extensive Law Code that God gave to His people (Colossians 2:13) and this Law Code was heavily dependent upon animal sacrifice for the blood from which sins were atoned for. (Leviticus 4:22-35,Leviticus 5:1-12,etc.). Christ's sacrificial death ended The Law Code, (Romans 10:4) therefore it was unnecessary for people to continue to adhere to The Law Code and the animal sacrifices (Hebrews 10:18).
DEATH & FORGIVENESS
Simply put, all of us are sinners (Romans 3:23). All of this sin came to us through one man: Adam (Romans 5:12, 1 Corinthians 15:22). The penalty for sin is death (Romans 6:7,23). Thus, our actual dying at the end of our lives is the payment for our debt of sin. Note that our own individual death pays for our own individual sin; but nothing in Scripture states that our individual death forgives us of our sins.
What is the difference between payment for sin and forgiveness of sin?
What does Jesus Christ have to do with all of this?
Therefore, when a non-believer rejects Christ this means that he or she is also rejecting this perpetual payment that Christ made. Consequently, this is also a rejection of the forgiveness that is tied to this payment. This is why those who refuse to believe in Christ have no Salvation – they cannot obtain freedom from their debt of sins if they do not accept the payment that frees them from it.
However – and it cannot be forgotten – this provision for forgiveness amongst believers is contingent on repentance. The idea of "once saved, always saved" is a false teaching, for one cannot gain forgiveness without the repentance (Hebrews 6:1-6). Obtaining Salvation doesn't mean that future sins can be committed without remorse. Just as John's baptism of repentance was the precursor to Christ's baptism of forgiveness, (compare Matthew 3:11 with Acts 2:38) so, too, our heartfelt repentance in Christ must precede the forgiveness from Christ. To knowingly commit a sin without repentance only serves to make a mockery of the wonderful gift that Jesus Christ gave us.
As believers we are told to live by God's example when it comes to forgiveness. This means that we are obligated to forgive others who sin against us when they are repentant if we are to expect God to forgive us when we are repentant (Matthew 6:14-15, Matthew 18:23-35, Mark 11:25, Luke 17:3-4, Ephesians 4:31-32, Colossians 3:13). This is the rule even if someone sins against us repeatedly (Matthew 18:21-22).
Although Scripture shows God withholds forgiveness towards people who are not repentant (2 Kings 24:4, Lamentations 3:42), this does not give us license to withhold forgiveness in the same way. Remember, God can judge a person's intentions because he knows what's in a person's heart (1 Samuel 16:7), whereas we, as humans, don't know what's really in a person's heart. To play God by refusing to offer forgiveness to an offender is an act of judgment on our part, and Jesus Christ tells us that God will judge us according to the way that we've judged others in our lives (Matthew 7:2). Parallel to this is the fact that if we don't offer forgiveness, then we won't receive forgiveness for our own sins (Matthew 6:12, 14-15). Therefore, not only do we need to keep watch over our own place in Christ's forgiveness, but we also need to keep watch over our willingness to forgive others as well.
Granted, offering forgiveness can be extremely difficult, especially in cases of paedophilia, murder, and extreme abuse. Nobody is saying that offering forgiveness is easy. However, it helps to know that God will take vengeance for those offenses (Romans 12:18-19, Hebrews 10:30). God must be the only one to take vengeance, not we ourselves, because only God can see what's in a person's heart (1 Samuel 16:7). Beyond that, even the most vile and wicked person has the potential to become a true worshiper of God later on (Acts 8:1-3 with 9:1-19, 1 Corinthians 6:9-11). It is understandable that in many cases, forgiveness will be a difficult thing to muster up and everyone struggles with forgiveness at one time or another. In many cases, it can take a person weeks, months, or even years to forgive – it's a natural response to our feelings of hurt and betrayal. If you find yourself stuck in this loop of being unable to forgive it is wise to pray for the wisdom and fortitude needed to offer the forgiveness.
As you are working your way through your feelings in your journey to forgive someone it is good to remember the basic framework that Scripture outlines regarding forgiveness: First, we must remember that everything we do must take place with love (1 Corinthians 16:14). Love means treating others humanely and without cruelty (Psalms 41:1, Proverbs 14:21, 28:27). We also need to be at peace with others as far as we possibly can (Romans 12:18). Scripture also tells us that we must treat our enemies with grace and kindness, as well as pray for them (Matthew 5:44-45). If your enemy is in need of something, you are to give what you can (Romans 12: 20). Simply put, continue treating the offender with Christian love.
WHEN WE NEED FORGIVENESS
What if you find yourself as the one needing forgiveness from another person?
The Scriptures tell us to seek forgiveness when we have wronged someone. This is so important that, if we are offering a gift in our place of worship and remember that someone has an issue with us, God prefers that we make peace with that person before giving the offering (Matthew 5:23-24). This is paralleled at Romans 12:18 which states that we must be peaceable with all. And don't become easily discouraged if your attempts at peace are not quickly accepted. Sometimes we have hurt people deeper than we realize, and it will take them time to work their way through the forgiveness process.
If you find yourself in that predicament then keep in prayer for that person and have patience. Don't be pushy, and do continue to offer brotherly love.
The only unforgivable sin is that of blaspheming the Holy Spirit. Any other sin can be forgiven (Matthew 12:31-32). The Scriptures show that blasphemy against the Holy Spirit is accomplished by speaking against the Holy Spirit, accusing the work of God as originating from something unholy (Mark 3:29-30). So, let us be sure to watch what we say and how we say it.
Summing it up, we see that God is always willing to forgive us when we repent, and even provided a way for us to be forgiven and saved from our own debt of sins. We are to live by the same idea: Forgive others who sin against us. We must remember to strive for repentance in order to benefit from God's divine forgiveness, and do our best to remain peaceable with all.