Is the "Holy Spirit" a leftover artifact from the days of Gnosticism?

Gnostics were the early Christian mystics who believed that Jahveh was evil (the Demiurge), Judas was Jesus' most trusted apostle and that the only way for salvation was through contemplating the sacred knowledge of the Divine. Sadly, they were all wiped out when Rome became Christian.

Nope. Not at all.

No the holy spirit is God.

They weren't all wiped out, the tradition has survived in a few corners of the world that no one bothered going until recently...

But honestly, it seems t have evolved alongside their tradition, not really being spawned from it, but definitely influenced by it. Paul wasn't a gnostic, and didn't obviously follow any gnostic, and yet ranted on about it endlessly.

Since the Holy Spirit was an Old Testament concept, the question is moot. Here's a couple of verses that specifically mention the Holy Spirit in the Old Testament, which preceded Gnosticism by centuries.

"Do not cast me from your presence or take your Holy Spirit from me." (Psalm 51:11)

"Yet they rebelled and grieved his Holy Spirit. So he turned and became their enemy and he himself fought against them. Then his people recalled the days of old, the days of Moses and his people-- where is he who brought them through the sea, with the shepherd of his flock? Where is he who set his Holy Spirit among them..." (Isaiah 63:10-11)

Thats not fair, you are asking Christians questions about the history of their religion. We both know the vast majority of them have absolutely no clue what you just said and you're using big words like gnosticism. The only history most Christians know is what has been favorably altered for them in their books.