Did you ask to be inspired?
"For everyone who asks receives; he who seeks finds; and to him who knocks, the door will be opened. Which of you fathers, if your son asks for a fish, will give him a snake instead? Or if he asks for an egg, will give him a scorpion? If you then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give the Holy Spirit to those who ask him!" - Jesus, as recorded in Luke 11:10-13
The context is His teaching on prayer. In one swell foop, He tells us that God loves us like a father and wants to give us good things; wants to give us the best gift of all - His Holy Spirt, but that we should ask. I get the impression that this describes how He wants to live through us, and it's not something to be taken lightly. And that it doesn't seem to be in His nature to just appropriate someone's body and do His will through them without their consent or request.
So there's really nothing to fear, is there?
Have you obeyed God?
"We are witnesses of these things, and so is the Holy Spirit, whom God has given to those who obey him." - Peter, as recorded by Luke in Acts 5:31
Oh, well; then no one is worthy of God's Spirit, because all have sinned and falled short of His glory. Sure, I've read Romans 3:23. That's the whole reason Jesus came. Not a proscription against Him being able to work through us. Remember, the same Peter speaking in in Acts 5:31 was the one whom Paul had to withstand face-to-face for refusing to eat with Gentiles.
Have you actively resisted the Holy Spirit?
"You stiff-necked people, with uncircumcised hearts and ears! You are just like your fathers: You always resist the Holy Spirit!" - Stephen, to the Sanhedrin, in Acts 7:51
Again, the implication to me is that the Spirit won't go where He isn't wanted.
Were you baptized into more than just the name of Jesus?
"When they arrived, they prayed for them that they might receive the Holy Spirit, because the Holy Spirit had not yet come upon any of them; they had simply been baptized into the name of the Lord Jesus. Then Peter and John placed their hands on them, and they received the Holy Spirit." - Luke, again, in Acts 8:15-17
I am admittedly going out on a limb here. What seems to be described here - to me - is an act of two apostles signifying by prayer and by resting their hands upon these Christians that they felt these believers should receive the Spirit without having to be re-baptized in the way Peter and John have described to them. That's making some assumptions, I admit. But Jesus requests that his disciples baptize in the name of the Father, the Son and the Holy Spirit in Matthew 28:16-20, and - unlike its companion passage in Mark 16 - these verses' authenticity is not generally questioned. And a similar thing happens with Paul in Acts 19.
Have you ever felt the power of overwhelming hope?
"May the God of hope fill you with all joy and peace as you trust in him, so that you may overflow with hope by the power of the Holy Spirit." - a blessing from Paul in Romans 15:13
Well then, if He brings such power it might seem logical - given the whirlwind, tongues of fire, healings and other miraculous manifestations connected to the giving of the Spirit in century one A.D. - that there could be no doubt about His presence in our lives in century twenty-one.
If there can be no doubt, why are would there be phrasings in scripture like these:
"It seemed good to the Holy Spirit and to us ...." - Acts 15:28a
"... I think that I too have the Spirit of God." - Paul, in I Corinthians 7:40b
That second verse is a study in the conflicting teachings of Paul and some other individuals whom Paul - rather graciously, "I think" - concedes have the Holy Spirit, even though they disagree on a matter that he qualifies "In my judgment."
I have to conclude that there are matters on which people can disagree and still be inspired by God's own Holy Spirit. Spiritual matters. Not just political parties or football teams or worship styles; but matters of life choice and destiny, such as whether to marry at a time when cataclysm is prophesied - the question at hand in this passage.
In other words, when there is no "right" answer.
And I have to conclude that the Spirit sometimes operates in us so subtly; so unobtrusively that we might even doubt His presence; or at least, not fully perceive it.
I think that's because God's plan involves faith and choice and free will.
I don't want to reduce His indwelling to some simplistic formula, for it is a matter much deeper and wider and more powerful and mysterious than any of us ultimately can grasp. But there are aspects of it that God wants us to know and understand, and be comforted by - that is one of the Spirit's primary concerns - and they are not too difficult to seek, to find, and to comprehend.