“Did you receive the Holy Spirit when you believed?” - Paul
“We have not so much as heard whether there is a Holy Spirit.” - Disciples in Ephesus
And when Paul had laid hands on them, the Holy Spirit came upon them, and they spoke with tongues and prophesied.
It is possible to be a believer and a disciple and not have heard about Holy Spirit.
Have you heard? If you are a disciple of Jesus (mathētēs - A pupil, committed student; a follower and learner of someone), according to the Bible, it is a basic, elementary part for a new believer's life. The world cannot receive Holy Spirit, but once you are reborn, and have a born-again spirit, then He can baptize you in Holy Spirit, because your spirit can contain what Jesus wants to immerse you into, giving you power for your life as a disciple of Jesus.