Rom 5:1 [Christ] was delivered for our offences (sins) and was raised again for our justification. THEREFORE, BEING JUSTIFIED BY FAITH, we have peace with god through our Lord Jesus Christ.”

Romans 3:21-25 (AMP) But now the righteousness of God has been revealed independently and altogether apart from the Law, although actually it is attested by the Law and the Prophets,

22 Namely, the righteousness of God which comes by believing with personal trust and confident reliance on Jesus Christ. [And it is meant] for ALL who believe. For there is no distinction, 23 Since ALL have sinned and are falling short of the honor and glory which God bestows and receives. 24 [ALL] are justified and made upright and in right standing with God, freely and gratuitously by His grace (His unmerited favor and mercy), Through The Redemption Which Is [Provided] ‘In Christ Jesus,’ 25 Whom God put forward [Before the Eyes of All] as a mercy seat and propitiation by His blood [the cleansing and Life-Giving sacrifice of Atonement and Reconciliation, to be received] through faith. This was to show God's righteousness, because in His divine forbearance He had (in ‘time past’) passed over and Ignored Former Sins Without Punishment.

Hebrews 9:22 … without shedding of blood is no remission (of sins).

In the Romans passage above, Paul doesn’t simply say that we are ‘forgiven’ of our sins in the way they were merely ‘covered’ before the cross (Rom 4:7). Forgiveness carries the idea that we have done harmed someone, and in forgiving us they try not to hold it against us. That’s not a sufficient solution by itself. This is because in Our Conscience we know that it leaves our sin still Unpunished and Undealt With. Humanly speaking, with forgiveness alone it depends wholly on the strength of will of the one harmed to continue to forget that we harmed them. We remain in their debt and it still holds a kind of power of extortion over us, even if they don’t intend to.

‘Justification’ is different and much greater than ‘forgiveness.’ God’s justification of us does not say; ‘You have done wrong, but I will try to forget it.’ Justification addresses the payment for the wrong done, and saying this was wrong, very wrong and unjust. God’s righteousness demands justice for sin - death (cf. Eze 18:4). Our sins needed to be Publicly Declared Wrong and Punished, so that all will know that Justice Was Served for our sins. Thus Jesus hung openly naked on the cross (cf. Mk 15:24), openly bearing the shame in paying for our sins.

Justification says, your sin was displayed openly before God’s eyes, thus the terrible open punishment Christ bore for us. When we say that we believe Christ died for our sins, we are not just forgivenwe are Openly JUSTIFIED. Believers MUST come to realize and appreciate that justice was fully served for their sins; otherwise we make the terrible death as the blood of the innocent “Lamb of God” slain for us to be of no account.

There is the big difference between forgiveness and justification. Forgiveness by itself leaves justice unsatisfied. It leaves sin unpunished but unjustified. Among the brethren, we have something greater than forgiveness with one another. We have the understanding that others sin against us has been declared unjust and wrong with the vengeance and violence Jesus suffered. Every sin of believers has been fully addressed by the vengeance and violence visited upon Jesus - for us. Trying to forget what they have done to me or that they are trying to forget what I have done to them is not the issue here. ONLY the blood of Jesus Christ has the power to deal with our sins, and it is most sufficient. Only His blood is sufficient to cleanse our ‘conscience.’

Hebrews 9:12 Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us. 13 For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh: 14 How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works (the ineffectual works of the Law) to serve the living God?

In the end, of ourselves, we can only forgive. We do not have the power to bear someone else’s punishment. But we can and should forgive others because what was needed has come: a Savior who justified us, who was qualitied to redeem our souls. In forgiving, we must not make the error of thinking that we are their savior, that we hold the power of attorney over them. True forgiveness on our part acknowledges that their justification in Christ is sufficient. Forgiveness under Christ is stronger than mere forgetfulness, it is constantly putting the sins of those around us under the terrible wrath displayed publicly on Christ at the cross. Justification is stronger and more lasting and makes more sense than forgiveness, because it accounts for the vengeance that our soul knows must be visited upon our sins.  

In Christ, our conscience is washed clean, and we are free indeed because we are justified freely through His shed blood for us!