Could you please be plainer?
What in your estimation is the grieving of the Holy Spirit and how could it come about that, for example IT, or me, could be prevented from entering the Kingdom of Heaven.
How could this come to pass?
Luke 12:10 And everyone who speaks a word against the Son of Man will be forgiven, but the one who blasphemes against the Holy Spirit will not be forgiven.
I can’t get any plainer than that. Don’t grieve the Holy Spirit. Don’t blaspheme the Holy Spirit. Don’t deny the Holy Spirit.
All other sins are forgiven. Completely and forever.