God will always sanctify you before He sends you. The Father set aside the twelve disciples and made them holy by the Truth, His Son. As they related to Jesus, the Truth (John 14:6), the disciples were refined by that Truth and were prepared to be sent out to preach the gospel. Jesus challenged their ambitions (Luke 9:46–48), chastised their lack of faith (Matt. 17:19–20), refuted Satan’s influence (Matt. 16:23), and denounced their pride (Matt. 26:33–35). When Jesus had finished preparing them, the disciples were sent out in such power that their world was never the same again.
Satan will try to convince you that your sin renders you useless to God. That is a lie from the author and father of lies. As soon as you sin, the Deceiver will whisper, “You failure! You are now of no use to God.” This can bring a deep sense of defeat and hopelessness to a Christian. Yet, there is no freedom that compares to a soul set free by God’s grace. When God’s people allow God’s truth to realign them to God’s will and God’s standard, then the power of God will be released through them the same way it was through the first disciples.
The Truth will set you free. The Truth is: “If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9), and we are restored to usefulness to God.