Who can forgive and cleanse us from sin?

Only God

^{Proverbs 17:15}

He who justifies the wicked and he who condemns the righteous, both of them alike are an abomination to the Lord [Johovah].

If any man tried to judge a righteous man, or any man tries to justify (make right, forgive) another man, they are an abomination to the Lord. If a man can officially/legally condemn another to hell, or justify the wicked person, then they are taking out the need and authority of God. Thus…

^{Mark 2:6-7}

But some of the scribes were sitting there and reasoning in their hearts, 7 “Why does this man speak that way? He is blaspheming; who can forgive sins but God alone?”

The Father

^{Jeremiah 33:8}

‘I [Jehovah] will cleanse them from all their iniquity by which they have sinned against Me, and I will pardon all their iniquities by which they have sinned against Me and by which they have transgressed against Me.

^{Psalm 51:1-2}

Be gracious to me, O God [Elohim], according to Your lovingkindness; according to the greatness of Your compassion blot out my transgressions. 2 Wash me thoroughly from my iniquity and cleanse me from my sin.

^{Psalm 103:11-12}

For as high as the heavens are above the earth, so great is His lovingkindness toward those who fear Him. As far as the east is from the west, so far has He removed our transgressions from us.

^{Isaiah 55:7}

Let the wicked forsake his way and the unrighteous man his thoughts; and let him return to the Lord, and He will have compassion on him, and to our God, for He will abundantly pardon. 

^{Ezekiel 36:24-26}

For I [Adonai Jehovah] will take you from the nations, gather you from all the lands and bring you into your own land. 25 Then I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your filthiness and from all your idols. 26 Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh.

^{Matthew 6:14-15}

For if you forgive others their trespasses, your heavenly Father will also forgive you, but if you do not forgive others their trespasses, neither will your Father forgive your trespasses.

^{Romans 4:5}

But to the one who does not work, but believes in Him [referring to the God who justified Abraham] who justifies the ungodly, his faith is credited as righteousness,

The Son

^{Matt 9:2-9/Mark 2:2-12/Luke 5:20-24/Luke 7:47-49}

…And Jesus seeing their faith said to the paralytic, "My son, your sins are forgiven." 6 But there were some of the scribes sitting there and reasoning in their hearts, 7 "Why does this man speak that way? He is blaspheming; who can forgive sins but God alone?"..

^{Luke 24:47}

and that repentance for forgiveness of sins would be proclaimed in His name to all the nations, beginning from Jerusalem.

^{Acts 5:31}

He is the one whom God exalted to His right hand as a Prince and a Savior, to grant repentance to Israel, and forgiveness of sins.

^{Ephesians 4:32}

Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you.

^{1 John 1:5-7}

5 This is the message we have heard from Him and announce to you, that God [the Father] is Light, and in Him there is no darkness at all. 6 If we say that we have fellowship with Him and yet walk in the darkness, we lie and do not practice the truth; 7 but if we walk in the Light as He Himself is in the Light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin.

The Spirit

^{1 Corinthians 6:11}

Such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ and in the Spirit of our God.

^{Titus 3:5}

He saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing [cleansing] of regeneration and renewing by the Holy Spirit

All three together

^{Matthew 28:18-19}

And Jesus came up and spoke to them, saying, “All authority has been given to Me in heaven and on earth. 19 Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit

^{Titus 3:4-7}

But when the kindness of God our Savior [The Father] and His love for mankind appeared, 5 He saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit [the Spirit], 6 whom He poured out upon us richly through Jesus Christ our Savior [The Son], 7 so that being justified by His grace we would be made heirs according to the hope of eternal life.