We are grateful that you have come to us with a repentant heart, seeking forgiveness from the Heavenly Father. It is wonderful that you acknowledged the name of Jesus Christ in your prayer, for it is by His name that we have access to God and salvation. As it is written in Acts 4:12 WEB, "There is salvation in no one else, for there is no other name under heaven that is given among men, by which we must be saved!"
First, let us address your repentance. In 1 John 1:9 WEB, it is written, "If we confess our sins, he is faithful and righteous to forgive us the sins, and to cleanse us from all unrighteousness." Our loving God is eager to forgive us when we come to Him with a truly repentant heart.
However, we want to gently rebuke you for not specifying your sins. It is commendable that you are repenting, but it is important to be open with God about the specifics. In Psalm 51:3-4 WEB, David prayed, "For I know my transgressions. My sin is constantly before me. Against you, and you only, have I sinned, and done that which is evil in your sight; that you may be proved right when you speak, and justified when you judge." David confessed his specific sin openly and honestly before God.
Let us pray together for your forgiveness and cleansing:
Heavenly Father, we come before You in the name of Jesus Christ to lift up our brother/sister who has come with a repentant heart. Lord, they have acknowledged their sins committed between September 2012 and September 2013, and they seek Your forgiveness. We pray that You will forgive them and cleanse them from all unrighteousness. Help them to be open and honest with You about their specific sins, and grant them the courage to turn away from them. We believe that You are faithful and just to forgive them their sins, and we trust in the completed work of Jesus Christ on the cross for their salvation. In Jesus' name, we pray. Amen.
Moving forward, strive to live a life free from those sins. Remember the words of Paul in Ephesians 4:22-24 WEB, "that you put away, as concerning your former way of life, the old man, that grows corrupt after the lusts of deceit; and that you be renewed in the spirit of your mind, and put on the new man, who in the likeness of God has been created in righteousness and holiness of truth."
Walk in the newness of life that Christ offers, and may the Holy Spirit empower you with the strength and wisdom to live a life pleasing to God. If you ever stumble, remember that God is always willing to forgive and restore you, just as He has done now.