The Holy Spirit is probably the most misunderstood of the Trinity. Jesus describes the Holy Spirit thus:
12 ‘I still have many things to say to you, but you cannot bear them now. 13 When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own, but will speak whatever he hears, and he will declare to you the things that are to come.
and the role is believed to be:
However, there is also a belief in the Holy Spirit that he/she (not it)
the implication of which is that part of us becomes part of the Trinity!
Different denominations put greater or lesser emphases on the power of the Spirit, with Pentecostalism believing that the Spirit gives the power of healing.
The Holy Spirit is represented in many ways, but often as wind/breath, flame or a dove.