Is there something like the Holy Spirit in Islam?
Yes. The Holy Qur’an speaks of the Spirit of holiness, and it means two things by it. On the one hand the Archangel Gabriel, who brings revelation, and on the other the lasting bond with God that makes a person holy. It is not a person beside God.
The Holy Spirit is not unique to Christianity. There it is stressed especially loudly, but it is found under one name or another in every religion. Without it no religion could exist at all, because without it there would be no revelation.
The first meaning is the angel responsible for revelation. He brings God’s word to the prophets and mixes nothing of his own into it. That is why he is called holy. The Holy Qur’an calls him the Spirit of holiness, and Muslims know him as the Archangel Gabriel.
The second meaning concerns every human being. It is the bond with God that makes a person lastingly pure. Many people sincerely regret their faults and yet fall back into the same ones. In those areas they have not yet found the Holy Spirit. But whoever earnestly wants to turn away from sin is helped by God. Once a person has truly become pure in one area, he stays pure, because this Spirit comes to stay. This journey lasts a whole lifetime, and it is not open to prophets alone.
This also makes the relation between law and spirit clear. Jesus (as) stressed the spirit of the law against those who kept only its outward form and were empty inside. But he did not abolish the law, or else the Ten Commandments would not have been kept either. Law and spirit belong together. One should follow the spirit of the law, but without the letter the spirit cannot survive.