What is the unpardonable sin and how can I be certain that I have not committed it?It is sobering to realize that the One who introduced the subject of a sin that can never be pardoned is the only Person in the world who is capable of forgiving sin — our Lord Jesus Christ, the Savior of all men.In Matthew 12:31,32, the Lord Jesus declared that "blasphemy or speaking profanely against the Holy Spirit" is the sin for which there was neither forgiveness in this world or the world to come. Thus, whoever is guilty of committing such a sin is "subject to eternal condemnation" (Mark 3:29, NKJV).It is vital that we understand the role of the Holy Spirit in God’s plan of salvation in order to grasp the Savior’s meaning of how one sins against the Holy Spirit. Only through the ministry of the Holy Spirit can a person know conviction of sin (John 16:8), be drawn to God (John 6:44; Revelation 22:17), and receive a revelation of the saving work of the cross of Christ (1 Corinthians 1:18; 2:14).Those who deliberately reject the only means by which God’s grace is mediated to lost sinners remove themselves from the only source of pardon provided by divine mercy. When Christ is willfully rejected, the Scripture states, "There no longer remains a sacrifice for sins" (Hebrews 10:26). Such a sin is called unpardonable because the basis for pardon has been rejected.Blaspheming the Holy Spirit is described as "insulting the Spirit of grace" (Hebrews 10:29). For when a person with full understanding of what he or she is doing "tramples the Son of God underfoot, and counts the blood of the covenant by which he was sanctified a common thing," the Holy Spirit is denied the opportunity to administer the grace and pardon of Christ.Regarding the unpardonable sin, J. Oswald Sanders wrote in his Bible Studies in Matthew’s Gospel: "These things should be noted: (1) It is a calculated sin, not one of impulse. (2) It is a sin of knowledge, not ignorance, but a sin against spiritual knowledge and light (Hebrews 10:26,32). (3) It is not an isolated act but a habitual attitude. (4) It is a sin of the heart, not merely of the intellect or the tongue. (5) It is a sin of finality — complete rejection of Christ." The harsh term "blasphemy" indicates a deliberate and godless rejection of the saving power and grace of God.Unfortunately, the devil has led some people to believe they have committed the unpardonable sin. People who are fearful they have committed such a sin would do well to heed the words of William Barclay: "The person who cannot have committed the sin against the Holy Spirit is the person who fears he/she has, for the sin against the Holy Spirit can be truly described as the loss of all sense of sin" (The Gospel of Matthew, Volume 2, p.50). The capacity to have concern regarding whether or not one has committed the unpardonable sin is a certain indicator the person has not done so.1 Corinthians 3:16Know ye not that ye are the temple of God, and [that] the Spirit of God dwelleth in you? Note 7 at 1 Cor. 3:16: One of the greatest differences between the New Testament believer and the Old Testament believer is the fact that New Testament saints are the temple of God. God Himself actually indwells us. In the Old Testament, the Spirit of God would come upon men and anoint them for service. He even came within Old Testament prophets to inspire them to write the scriptures, but this was temporary. In the New Testament, the Lord indwells us through the new birth and we become His permanent abode (see note 26 at Jn. 14:16, p.491). During the days of the Old Testament, man made God an elaborate temple in Jerusalem and God said He would cause His name to dwell there so that men could pray to Him in that place (2 Chr. 7:12-16). But now, in the days of the New Testament, God does not dwell in a building made by man's hands. He now lives in the hearts of those who make Jesus their Lord (Rom. 10:9). This is why there is no need for fancy buildings for the New Testament church to meet in. The building is no longer the temple of God. The believer's spirit has become the temple of God. However, the New Testament is clear that Christ, by the Holy Spirit takes up permanent residence in all believers If we had a real revelation of the reality of Christ in us (Col. 1:27), it would drastically change our attitudes, emotions, and actions. This is not speaking of God totally damning someone who defiles the temple of God. However, no degree of punishment from God is desirable and therefore, this is a very stern warning to those who would defile the body of Christ through their wrong teaching. Therefore, Paul's teaching here about defiling the temple of God is speaking specifically to an individual about doing something to defile himself, and it is rather a warning against anyone defiling the church with wrong teaching. This would include Paul and Apollos (1 Cor. 3:5-6), but it also would refer back to those individuals who Paul rebuked in the first chapter for causing division in the body at Corinth. This is a warning, especially to ministers, that they had better make sure they are speaking God's Word for they will have to give an account to God.