What is meant by “the Holy Spirit cannot dwell in an unclean place”?
The phrase in question, namely “the Holy Spirit cannot dwell in an unclean place”, is not a quote from Scripture, thus we must assume that it’s someone’s theological opinion. It would be necessary to know the context of this statement in order to determine what the intended meaning may be. For the sake of proposing an answer, I will assume that someone is of the opinion that God, the Holy Spirit cannot dwell in an unclean person, particularly, an unclean Christian. I will further assume an “unclean” Christian is a believer who is living in known sin.
The Bible teaches that when a sinner receives Christ as Savior, the person is “baptized into one body” or immersed in the family of God by the regenerating power of the Holy Spirit (1 Corinthians 12:13). This happens once at the time of conversion. It is at this time that the person is “indwelt” by the Holy Spirit (Romans 8:15-16).
Then, as the Christian yields to the Holy Spirit’s leading in their life, they are “filled” with the Spirit, thus are controlled by the Spirit (Galatians 5:16, Ephesians 5:16). But even when the believer may stray into sin, the Holy Spirit remains to convince the child of God that they are sinning (1 Corinthians 6:19-20). The Holy Spirit is the presence of God in the believer’s life to lead them to confession of sin and eventual forgiveness (1 John 1:9).
In reality, the Holy Spirit of God does dwell in the “unclean place” of the believer’s body. What I mean by this is that the believer still possesses the uncleanness of sinful tendencies after conversion, but the Holy Spirit is still willing to dwell within the believer.
One possible meaning of the Holy Spirit not dwelling in an unclean place is that the Holy Spirit does not dwell in an unbeliever (Romans 6:8). But, once a person is a true believer, he or she will be permanently indwelt with the Holy Spirit until the day of redemption when they get to Heaven.