Matthew 18:21-35 (KJV)
21 Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times?
22 Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven.
23 Therefore is the kingdom of heaven likened unto a certain king, which would take account of his servants.
24 And when he had begun to reckon, one was brought unto him, which owed him ten thousand talents.
25 But forasmuch as he had not to pay, his lord commanded him to be sold, and his wife, and children, and all that he had, and payment to be made.
26 The servant therefore fell down, and worshipped him, saying, Lord, have patience with me, and I will pay thee all.
27 Then the lord of that servant was moved with compassion, and loosed him, and forgave him the debt.
28 But the same servant went out, and found one of his fellowservants, which owed him an hundred pence: and he laid hands on him, and took him by the throat, saying, Pay me that thou owest.
29 And his fellowservant fell down at his feet, and besought him, saying, Have patience with me, and I will pay thee all.
30 And he would not: but went and cast him into prison, till he should pay the debt.
31 So when his fellowservants saw what was done, they were very sorry, and came and told unto their lord all that was done.
32 Then his lord, after that he had called him, said unto him, O thou wicked servant, I forgave thee all that debt, because thou desiredst me:
33 Shouldest not thou also have had compassion on thy fellowservant, even as I had pity on thee?
34 And his lord was wroth, and delivered him to the tormentors, till he should pay all that was due unto him.
35 So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses.

We now know a little more about forgiveness so today we will discover who actually can forgive sins.
In short GOD and people can forgive sin. It is obvious that GOD can do this.
The most important thing to know is that Jesus Christ paid the price for all our sins (one and for all) a price we can not pay ourself. “Hebrews 10:16-18 (KJV) This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them; [17] And their sins and iniquities will I remember no more. [18] Now where remission of these is, there is no more offering for sin.”

The bible is riddled with examples of GOD’s forgiveness and mercy :

• “Exodus 34:6-7 (KJV) And the LORD passed by before him, and proclaimed, The LORD, The LORD God, merciful and gracious, longsuffering, and abundant in goodness and truth, [7] Keeping mercy for thousands, forgiving iniquity and transgression and sin, and that will by no means clear the guilty; visiting the iniquity of the fathers upon the children, and upon the children’s children, unto the third and to the fourth generation.”
• “Psalms 85:2-3 (KJV) Thou hast forgiven the iniquity of thy people, thou hast covered all their sin. Selah. [3] Thou hast taken away all thy wrath: thou hast turned thyself from the fierceness of thine anger.”
• “Psalms 103:2-4 (KJV) Bless the LORD, O my soul, and forget not all his benefits: [3] Who forgiveth all thine iniquities; who healeth all thy diseases; [4] Who redeemeth thy life from destruction; who crowneth thee with lovingkindness and tender mercies;”
• “Mark 2:5-12 (KJV) When Jesus saw their faith, he said unto the sick of the palsy, Son, thy sins be forgiven thee. [6] But there were certain of the scribes sitting there, and reasoning in their hearts, [7] Why doth this man thus speak blasphemies? who can forgive sins but God only? [8] And immediately when Jesus perceived in his spirit that they so reasoned within themselves, he said unto them, Why reason ye these things in your hearts? [9] Whether is it easier to say to the sick of the palsy, Thy sins be forgiven thee; or to say, Arise, and take up thy bed, and walk? [10] But that ye may know that the Son of man hath power on earth to forgive sins, (he saith to the sick of the palsy,) [11] I say unto thee, Arise, and take up thy bed, and go thy way into thine house. [12] And immediately he arose, took up the bed, and went forth before them all; insomuch that they were all amazed, and glorified God, saying, We never saw it on this fashion.”

This brings us to answer the question “if we can forgive sins?”. According to the above verse we can’t but this was the answer of religious people who rejected Jesus Christ.
Jesus Christ Himself said that we who are in Him can. “John 20:21-23 (KJV) Then said Jesus to them again, Peace be unto you: as my Father hath sent me, even so send I you. [22] And when he had said this, he breathed on them, and saith unto them, Receive ye the Holy Ghost: [23] Whose soever sins ye remit, they are remitted unto them; and whose soever sins ye retain, they are retained.”

Therefore let us be encourages to be quick to forgive others and not hold grudges. Let us be determined to be a blessing and not a curse to those around us. In “Ephesians 4:30-32 (KJV) it exhorts us to put a way all the things that come form unforgiveness and instead to forgive one another. “And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption. [31] Let all bitterness, and wrath, and anger, and clamour, and evil speaking, be put away from you, with all malice: [32] And be ye kind one to another, tenderhearted, forgiving one another, even as God for Christ’s sake hath forgiven you.”
Our forgiveness allows GOD to minister to the heart of the other person being forgiven. Sometimes and some things require a process of forgiveness and we need to not try to keep on recalling what happened. “Philippians 3:12-15 (KJV) 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. [13] Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, [14] I press toward the mark for the prize of the high calling of God in Christ Jesus. [15] Let us therefore, as many as be perfect, be thus minded: and if in any thing ye be otherwise minded, God shall reveal even this unto you.”
One important thing to realise is that only the LORD can give us the capacity to fully forgive as we see in Galatians 5:22-23 (KJV) “But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, [23] Meekness, temperance: against such there is no law.”