The unforgivable sin that the Holy Spirit will only convict of is unbelief since it is unbelief as in a sinner that never had believed in Him to receive that foundation and that seal of adoption, is why they go to hell and the lake of fire as the Holy Spirit not being in them may be how they are condemned.
Otherwise what Jesus said here in John 6:39 cannot be true nor Ephesians 4:30 nor 1 John 1:9 for the saved believers.
Revelation 3:5 He that overcometh, the same shall be clothed in white raiment; and
I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels.
From Strong's Concordance on the Greek words "ou me" from which the English word "not" was translated from; "i.e. ou - ou
3756 and mh - me
3361; a double negative strengthening the denial; not at all:--any more, at all, by any (no) means, neither, never, no (at all), in no case (wise), nor ever, not (at all, in any wise). Compare mh ouk - me ouk
3378."
It is a double negative as in there is no case whatsoever for a believer to have his or her name blot out of the Book of Life.
Everyone is saved from the born again of the Spirit though, but whether or not how they run that race aka what they built on that foundation will be judged as to whether or not they are received as vessels unto honor in His House of the firstfruits of the resurrection when the Bridegroom comes or resurrected later on after the great tribulation as that vessels unto dishonor in His House is the question of the times we are living in for each believer to ask Jesus about at that throne of grace for help to be ready & willing to go or else.