Because the blasphemy of the Spirit is a willful suppression of the truth about Christ, theologians agree that Christians who worry if they have committed the sin have likely not done so. Those who willfully deny the truth would have no concern for the state of their souls, for they have chosen consciously not to affirm what they know to be real. Pray that you would never suppress God’s truth and ask Him to reveal Himself to you through His Word.
Are you afraid that you’ve committed the unpardonable sin? If you are concerned about it, you can be assured that you haven’t committed it. Have you purposely called the work of the Holy Spirit the work of the devil? Have you seen the truth about Christ, known it to be true, but called it a lie? If not, you have not committed this sin.