Cornelius’s household received the Holy Spirit when hearing “forgiveness of sins.”

No altar call.
No music.
No long prayer.

Just one sentence.

Peter preached:

“Everyone who believes in Him receives forgiveness of sins.”
Acts 10:43

And immediately:

“The Holy Spirit fell on all who heard the word.”
Acts 10:44

The Spirit came not because they promised change or proved sincerity,
but when they heard and believed they were forgiven.

Forgiveness opened the door.
Faith walked through it.
The Spirit filled the room.

This is the simplicity of the gospel:
God moves the moment you believe He has already forgiven you.