The Holy Spirit can live in a human and actually every believer in Jesus Christ possesses the Holy Spirit – without the Holy Spirit one cannot believe. One of the incomprehensibles of Christianity is that the Almighty God desires to live in the heart of a small and sinful human being.

The Holy Spirit comes to a human heart through the Word of God and through the sacraments - the baptism and the Holy Communion. By using these means of grace the Holy Spirit awakens a saving belief in Jesus Christ in a human heart and makes one a child of God. A child of God can however, with his/her disobedience, grieve the Holy Spirit and fall back in disbelief. That is why the Bible warns about hardening of the heart and apostasy and advices one to return to the only Savior.

You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.
(Romans 8:9, ESV)