Dear Hischild,
 
St. Paul states in Romans 7:17-25 says that he performs evil sometimes when he wants to do good, because of the sin that dwells in his flesh, and St. Peter denied Christ three times. You must admit that the instigation of the Holy Spirit does not always fall into place as you state.
 
So unless you are a greater saint than Paul and Peter, then I will assume you also do things that are contrary to the instigation of the Holy Spirit, simply because your spirit still dwells in an unsaved fleshly body, similar to the state of St. Paul and St. Peter. They were both saved and believed in Jesus.
 
You are in error, I think, to believe that anyone who is saved and believes in Jesus finished work at Calvary and does good works, most of the time, cannot fall into sinful works. There is always forgiveness, if that person later asks for forgiveness. That is why John wrote in 1 John 1:9 "If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness."
 
Take care.
 
YBIC,
Robert