Bible talked about the sin against the holy ghost.
Can anyone help us to understand the kind of sin that is without forgiveness? happy Sunday all

I don't know if I would term it "eternal sin", although I get what you're saying brother.
You're saying the sin that would cause one to lose eternity with Christ.
The sin against the Holy Spirit is to reject the Spirit's role in a person's life (be it followers of Christ or non-believers)...cause the Spirit speaks to their hearts as well.
It's a gradual process of ignoring the calm, inner pleadings and promptings of the Spirit trying to identify, convict, and correct one of sin in his/her life.
If a person continues to choose to reject Him (the Holy Spirit), then there becomes no pardon or grace given.
If a person sees no need of conversion from a sinful life, then how can he/she be saved into the Kingdom?
The danger in continual rejection is that one can never know when he/she will meet death..
The Lord is extremely long-suffering, but He won't force and there comes a time when He has to accept a person's choice.