I believe these verses in Matthew 12:31-32 refute the possibility of post-mortem faith.
Matthew 12:31-32 " Therefore I say to you, any sin and blasphemy shall be forgiven people, but blasphemy against the Spirit shall not be forgiven. Whoever speaks a word against the Son of Man, it shall be forgiven him; but whoever speaks against the Holy Spirit, it shall not be forgiven him, either in this age or in the age to come."
The sin was the Pharisees’ deliberate unbelief of what they knew to be of God.( Miracles, healings, message, etc) Those who reject the gospel message sin against the Holy Spirit- because it is the Holy Spirit that testifies of Christ and makes the truth known to us.( John 15:26; 16:14,15) No forgiveness was possible for these Pharisees who witnessed Jesus’ miracles first-hand, knew the truth of His claims, and still blasphemed the Holy Spirit- because they had already rejected the fullest possible revelation.( Hebrews 10:29). So, Unbelief is the unpardonable sin, in this life and the next. Look forward to your comments.