Question: "What does the Bible say about confession of sin to a priest?"
Answer: The concept of confession of sin to a priest is nowhere taught in Scripture. First, the New Testament does not teach that there are to be priests in the New Covenant. Instead, the New Testament teaches that all believers are priests. First Peter 2:5-9 describes believers as a “holy priesthood” and a “royal priesthood.” Revelation 1:6 and 5:10 both describe believers as “a kingdom of priests.” In the Old Covenant, the faithful had to approach God through the priests. The priests were mediators between the people and God. The priests offered sacrifices to God on behalf of the people. That is no longer necessary. Because of Jesus’ sacrifice, we can now approach God’s throne with boldness (Hebrews 4:16). The temple veil tearing in two at Jesus’ death was symbolic of the dividing wall between God and humanity being destroyed. We can approach God directly, ourselves, without the use of a human mediator. Why? Because Jesus Christ is our great High Priest (Hebrews 4:14-15; 10:21) and the only mediator between us and God (1 Timothy 2:5). The New Testament teaches that there are to be elders (1 Timothy 3:1-7; Titus 1:6-9), deacons (1 Timothy 3:8-13), and pastors (Ephesians 4:11) – but not priests.
When it comes to confession of sin, believers are told in 1 John 1:9 to confess their sins to God. God is faithful and just to forgive our sins as we confess them to Him. James 5:16 speaks of confessing our trespasses “to one another,” but this is not the same as confessing sins to a priest as the Roman Catholic Church teaches. Priests / church leaders are nowhere mentioned in the context of James 5:16. Further, James 5:16 does not link forgiveness of sins with the confession of sins “to one another.”
The Roman Catholic Church bases their practice of confession to a priest primarily on Catholic tradition. Catholics do point to John 20:23, “If you forgive anyone his sins, they are forgiven; if you do not forgive them, they are not forgiven.” From this verse, Catholics claim that God gave the apostles the authority to forgive sins and that authority was passed on to the successors of the apostles, i.e., the bishops and priests of the Roman Catholic Church. There are several problems with this interpretation. (1) John 20:23 nowhere mentions confession of sin. (2) John 20:23 nowhere promises or even hints that apostolic authority of any kind would be passed on to the successors of the apostles. (3) The apostles never once in the New Testament acted as if they had the authority to forgive a person’s sin. Similarly, Catholics point to Matthew 16:19 and 18:18 (binding and loosing) as evidence for the Catholic Church’s authority to forgive sins. The same three above points apply equally to these Scriptures.
The ability to forgive sins is God’s and His alone (Isaiah 43:25). The better understanding of John 20:23 is that the apostles were given the responsibility of declaring with utmost certainty the terms on which God would forgive sins. As the church was being founded, the apostles declared that those who believed the gospel were forgiven (Acts 16:31) and those who did not obey the gospel faced judgment (2 Thessalonians 1:8; 1 Peter 4:17). As the apostles proclaimed salvation in Christ (Acts 10:43) and exercised church discipline (1 Corinthians 5:4–5), they were wielding the authority Christ had given them.
Again, the concept of confession of sin to a priest is nowhere taught in Scripture. We are to confess our sins to God (1 John 1:9). As New Covenant believers, we do not need mediators between us and God. We can go to God directly because of Jesus’ sacrifice for us. First Timothy 2:5 says, “For there is one God and one mediator between God and men, the man Christ Jesus.”