If you're new to Old Testament history, this is going to be a confusing chapter. The truth it conveys is very simple: God removes our sin.
Zechariah 3 shows us the High Priest--the one who was supposed to offer sacrifices on behalf of the whole nation, and ask God to forgive their sins. But he was dressed in dirty clothing and Satan was accusing him of sin. The Lord rebuked Satan, and gave Joshua new clean clothes.
This is a vivid picture of the Christian life. When we accept the Lord as our Savior, He forgives our sin. All of it. Yesterday's sin, today's sin, tomorrow's. But sometimes we begin to feel guilty. In fact, Satan wants us to feel guilty. He wants us to question whether we are worthy to serve God.
We can choose to listen to God's word and believe that we are forgiven and He has clothed us in His righteousness--and stop carrying a load of guilt!
All we like sheep have gone astray; we have turned—every one—to his own way; and the Lord has laid on him the iniquity of us all. (Isaiah 53:6)
If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. (I John 1:9)
To the praise of his glorious grace, with which he has blessed us in the Beloved. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace, which he lavished upon us, in all wisdom and insight. (Ephesians 1:6-8)
God has poured out His grace on us. He does not forgive or bless grudgingly or a little at a time. He gives us the riches of His grace, lavishly! Here are those verses in Ephesians, from the NLT version:
So we praise God for the glorious grace he has poured out on us who belong to his dear Son. He is so rich in kindness and grace that he purchased our freedom with the blood of his Son and forgave our sins. He has showered his kindness on us, along with all wisdom and understanding. (Ephesians 1:6-8)
I pray that you will praise God for His glorious grace today.