Isaiah, Peter, and Paul found themselves unworthy, but because of God’s mercy and grace, they found the confidence to do God’s work (Isaiah 6:1-8) (Luke 5:1-11) (1 Corinthians 15:9-11). Perhaps part of spiritual growth is the “realization that the closer we approach God, the more we become aware of our own sins (Geneva Bible Notes).”
Nevertheless, God’s grace and mercy overcomes our unworthiness and qualifies us to do God’s work. God can work through you, and God has a work, for you in a congregation of Christ’s Church and in your community. Saying, “I’m unworthy” is an honest admission of our failings, but let it not be an evasion to not do God’s work.