God is pretty awesome. He’s three persons in one—the Father, the Son, and the Holy Spirit. It’s a great mystery and doesn’t always make sense (kinda like how Jesus is 100% man AND 100% God or how the Eucharist is the Body, Bloody, Soul, and Divinity of Jesus yet looks nothing like Him). God works outside of what we typically think of as reality because, even though He is totally real, He operates beyond our comprehension. The Trinity (Father/Son/Holy Spirit) is difficult for many people to understand.
God, refers to all three Persons, but sometimes we forget about the Holy Spirit. The Holy Spirit came down upon the disciples like tongues of fire at Pentecost. But perhaps we don’t understand the Spirit because it is in the Church where we get to know the Spirit. Maybe we either aren’t attending Mass every Sunday… and maybe we should even be there for daily Mass!
The Holy Spirit does a lot: He inspired Sacred Scripture, Sacred Tradition, and the Magisterium (teaching body of the Church). He also intercedes for us in prayer. When we forget about the Holy Spirit, we forget about one third of our Trinitarian God. So pray with me: Come Holy Spirit!