In the third part of the interview, Elder Thaddeus talks about the sin of the blasphemy against the Holy Spirit that it is not pardonable, not in this age nor the age to come (Matt. 12:31).
He brings the teaching of the Holy Fathers stating that this sin means persisting on non-repentance and opposing the Truth.
He also relates some stories from the Miljkovo Monastery, where he lived as a novice in obedience to Elder Ambrose, a disciple of the Optina Elders. It would often happen to Fr. Thaddeus to be lost in thoughts, and when reading a lot he did not pay attention to the sheep, the cows he had to oversee… you can easily imagine the consequences…
What is the blasphemy against the Holy Spirit? Not in this age nor the age to come will not be forgiven.
Holy Fathers say that the blasphemy against the Holy Spirit is the persistence on non-repentance. Persisting on non-repentance and opposing the Truth. It cannot be forgiven, because a man does not want to repent.
If our thoughts are peaceful, quite, full of love, we do not fight with anyone in our thoughts. With our thoughts we attract or reject others.
If nobody touches us, we think we are alright. “I have been in the monastery for a long time, I pray to God” etc. The devil puts those thoughts so that you think you have some value. Actually, there is nothing.