Acts 3:19

Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord;

The entire chapter of Acts 3 is about a lame man that Peter healed, and when people saw him healed, everyone wanted in on Peter's "power," but Peter reminded them how they rejected God and how they should repent. Remember, God is ready to forgive you.