There is no place in the whole of Scripture where Jesus or the Apostles say that only God can forgive sins.
I have an Evangelical friend, who got caught up in a homosexual relationship with her roommate. She decided to confess her sins to her church because of what Scripture says in James 5, "confess your sins to one another." She got up in front of her whole congregation and confessed what she had been doing. My compliments to her, this had to take a great deal of humility. I asked her what the response was of the many people, who listened to her Confession. She said "they didn't know what to do with it!" Interesting response, perhaps this is one of the reasons why Jesus gave the Apostles the power to forgive and retain sins.
Jim Kerr, commenting on social media, cites Mark 2:7 as proof that confessing sins to a priest is wrong, “Why does this man speak this way? He is blaspheming. Who but God alone can forgive sins" (Mk. 2:7)? He went on to say that only God can forgive sins, and Christ, being God, has the power to do so as well! Let’s give Jim credit for getting a couple of things correct. He said God can forgive sins. This is correct. He said; Christ is God, correct. And he is saying in reference to sin, God has the power to forgive sins, correct. However, he is incorrect when he limits Confession of sin to God alone, without man involvement.
This is Jim's thinking, coming from his tradition, not the Bible. He doesn't seem to know the part of his Bible that says we should confess our sins to one another. "So confess your sins to one another, and pray for one another to be cured; the heartfelt prayer of someone upright works very powerfully" (Jm. 5:13-20). And his tradition does not allow him to accept the words of Jesus (John 20:21-23) when He breathes on the Apostles and gives them the power to forgive and retain sin. Jim isn't the only one. Some will even say that to confess your sins to another is making man into a mediator in place of Christ as mediator.
Jim attempts to prove that the Catholic Church is wrong because in Confession the priest is given the power to forgive and retain sins. He points to Mark 2:7 which says "God alone can forgive sins." This then begs the question, if only God can forgive sins then why is the priest forgiving sin? Has the Catholic priest become a God in place of Jesus? Why does this man speak this way? He is blaspheming. Who but God alone can forgive sins" (Mk. 2:7)? Jim isn't the only one, who sees it this way; there are hundreds of thousands if not millions who see it this way.
Here is the way the argument goes; the non-Catholic cites Mark 2:7 to prove that God alone apart from man can forgive sins and the Catholic responds by quoting John 20:21-23 to show that Jesus has given the Apostles the power to forgive and retain sins. Those of us who listen to this then are put in the position, should we follow Mark 2:7 or John 20:21-23. The Catholic understanding of Scripture in general, which is also embraced by most Protestants, is that Scripture properly understood in context does not contradict and is the inspired word of God. And so, the question is this, is the Gospel in Mark at odds with the Gospel in John? Is there any way of reconciling Mark 2:7 with John 20:21-23?
The single most important question we should ask is who said that only God can forgive sins? Was it Jesus or the Apostles?
In many cases people will not know the answer to this question. The answer is neither, it was the scribes, who opposed Jesus, who said it. Usually when people quote Mark 2:7, they don't include verse 6 because now we know it was the scribes who opposed Jesus who made this statement "Now some of the scribes were sitting there asking themselves, "Why does this man [Jesus] speak that way? He [Jesus] is blaspheming. Who but God alone can forgive sins" (Mk. 2:6-7)?
And so, people who believe that God alone can forgive sins are not followers of Jesus, but followers of the Scribes, who opposed Jesus. I then asked, who would you rather follow the scribes, who opposed Jesus and said "Who but God alone can forgive sins?" Or would you rather follow Jesus who breathed on the Apostles and gave them the power to forgive and retain sins. "Peace be with you. As the Father has sent me, so I send you." And when he had said this, he breathed on them and said to them, "Receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained” (Jn. 20:23).
When, I first posted this on social media someone objected to my pointing out that the citation was from the scribes, who opposed Jesus, and not Jesus. This person claimed that it didn't matter that the scribes were the ones who said "God alone can forgive sins." He explained to me that we have to believe it anyway because it is in Scripture, part of the inspired word of God, and so we have to believe it.
I asked him this question, "do we also have to believe these same scribes when they accused Jesus of blasphemy?" After all this is in Scripture part of the inspired word of God as well. "He [Jesus]is blaspheming. Who but God alone can forgive sins" (Mk. 2:7)? He then became strangely silent and said no more. We don't believe that everything in Scripture, by itself, is the inspired word of God. We do believe that Scripture properly understood in context is inspired by God.
So strong are their man-made traditions that many people do not believe the Apostles had the power to forgive and retain sins even though Jesus gave them this power! There will always be people who will insist that only God can forgive sins with no involvement of the Apostles. However, they are the followers of the Scribes, who accused Jesus of blasphemy. As for me, I follow Jesus and He was the one who gave the Church through the Apostles the power to forgive sins; “Whose sins you forgive are forgiven them, and whose sins you retain are retained” (Jn. 20:23).
Non-Catholics who reject the notion of man involvement in the forgiveness of sins do in fact have a Biblical precedent; however, they are following the Scribes who rejected Jesus. Catholics who believe in man involvement in the forgiveness of sins have a Biblical precedent as well and are following Jesus.
Who will you follow?
Will you believe the Scribes who accused Jesus of blasphemy or will you believe Jesus who gave the Apostles the power to forgive and retain sins?
Luther defends confession: "small Catechism by Martin Luther" Martin Luther understood the words of Jesus and man involvement in the forgiveness of sins and absolution. Luther had this to say about confession in his Catechism.
What is confession? Answer, "We receive absolution and forgiveness from the confessor, as from God Himself, and in no wise doubt, but firmly believe, that by it our sins are forgiven before God in Heaven.
What sins should we confess? Answer, "Before God we should plead guilty of all sins, even of those which we do not know, as we do in the Lord’s prayer; but before the confessor we should confess those sins only which we know and feel in our hearts" http://bookofconcord.org/smallcatechism.php#preface.
The Catholic Defender: Absolution in the Confessional, it is most important https://www.deepertruthcatholics.com/single-post/2018/03/05/The-Catholic-Defender-Absolution-in-the-Confessional-it-is-most-important
Top 10 Bible Verses on Penance: http://taylormarshall.com/2011/03/for-lent-top-10-bible-verses-on-penance.html
What is the Apostolic Pardon? https://aleteia.org/2017/03/23/what-is-the-apostolic-pardon/
Myths about Indulgences https://www.catholic.com/tract/myths-about-indulgences
Why Do Penance? - Jimmy Akin https://www.youtube.com/watch?v=0cmckKxwkXM&feature=youtu.be&app=desktop