How do we know the unpardonable sin is true?

The truth of the unpardonable sin is affirmed through various scripture passages that warn about the consequences of unbelief. For instance, Hebrews 10:26-27 states that if one continues in willful sin after receiving knowledge of the truth, there remains no sacrifice for sins, only a fearful expectation of judgment. This underlines how critical it is to not only hear but embrace the message of the gospel. Additionally, John 3:36 emphasizes that whoever believes in the Son has eternal life, while whoever does not obey the Son shall not see life, but the wrath of God remains on him. Therefore, the biblical perspective reinforces that rejecting the gospel is indeed a grave matter, validating the concept of the unpardonable sin.