From The Life and Times of Bruce Gerencser:
Many Baptists believe that the moment a person is saved, the Holy Spirit takes up permanent residence inside of them. Now, that’s only for people who are saved after the resurrection of Jesus. Those saved before the resurrection of Jesus — say people in the gospels and the Old Testament — the Holy Spirit came upon them when he needed to use them in some sort of powerful, supernatural way. Once this was accomplished, the Holy Spirit departed.
Other Baptists believe that the Holy Spirit has always lived in saved people — both before and after the resurrection of Jesus. These Baptists see a continuity between the Old and New Testaments. This belief is popular among worshippers of John Calvin.
And yet other Baptists believe that all saved people are indwelt by the Holy Spirit, but “special,” on-fire, sold-out Christians can receive a special outpouring of the Holy Spirit if they really, really, really beg God to give it to them. Some preachers I heard growing up called this being baptized with the Spirit.
Wander off into the Evangelical weeds and you will find all sorts of additional — and contradictory — beliefs about the Holy Spirit. Some sects believe that you receive the Holy Spirit the moment you are baptized by immersion. Other sects believe similarly, except the evidence of being filled with the Holy Spirit is speaking in tongues. What is speaking in tongues, you ask? Ah yes, another belief Christians are hopelessly divided over.