When Jesus sent out the 12 in Matthew 10th chapter after giving them a temporary Holy Ghost as that "power" was given to them, He said this;
Matthew 10:19 But when they deliver you up, take no thought how or what ye shall speak: for it shall be given you in that same hour what ye shall speak. 20 For it is not ye that speak, but the Spirit of your Father which speaketh in you.
Jesus did not say seek or pray for a filling of the Spirit before they were to speak as everything should be done by faith.
So when you read the events in Acts that Reformed Theology/Calvinism seem to place this "continual filling" of the Holy Spirit from, do note the use of the term "filled with the Spirit" as in past tense to signify how the disciples were answering or doing the things they were doing rather than they just received a filling of the Spirit "again" in order to do those things.
Acts 4:7 And when they had set them in the midst, they asked, By what power, or by what name, have ye done this? 8 Then Peter, filled with the Holy Ghost, said unto them, Ye rulers of the people, and elders of Israel,
They had asked that question and verse 8 is signifying how Peter spoke as led by the Spirit to inform readers he was not answering from himself.
Acts 13:8 But Elymas the sorcerer (for so is his name by interpretation) withstood them, seeking to turn away the deputy from the faith. 9 Then Saul, (who also is called Paul,) filled with the Holy Ghost, set his eyes on him. 10 And said, O full of all subtilty and all mischief, thou child of the devil, thou enemy of all righteousness, wilt thou not cease to pervert the right ways of the Lord?
That was how Paul said the things that he did since Paul could not have known that to render such a judgment but the Lord through the Holy Spirit in Paul, said that as Paul filled with the Holy Ghost with none of his flesh or his own intellect speaking that at all.
Acts 13:48 And when the Gentiles heard this, they were glad, and glorified the word of the Lord: and as many as were ordained to eternal life believed. 49 And the word of the Lord was published throughout all the region. 50 But the Jews stirred up the devout and honourable women, and the chief men of the city, and raised persecution against Paul and Barnabas, and expelled them out of their coasts. 51 But they shook off the dust of their feet against them, and came unto Iconium. 52 And the disciples were filled with joy, and with the Holy Ghost.
Now to the readers, how can they behave like that after such a work of the Lord did in that region? Why weren't they mad and just march right back into that region to defy those who kicked them out? To the religious flesh, it would seem confusing how they could have just walked away after seeing all that the Lord had done in that region, but they did so as led by the Lord as they were filled with the Holy Ghost to do so, even to have joy ( which is a fruit of the Spirit also )
So that is an example of how they could have done that, not that afterwards, they received a supernatural filling of the Holy Ghost in order for them to walk away with joy in doing that for they have been filled with the Holy Ghost for how they had done that ministry & walking away.
Of course, Acts 2;4 was when His disciples were saved as well as Paul in Acts 9:17 but for Acts 4:31, was when the company of potential 5,000 believers were saved since they became a new community of believers, selling all that they had and given it to the apostles to distribute evenly among that new community of believers. They had prayed that they would preach like Peter & John after hearing what had happened to them when they got arrested and then acting on their belief finally so that was when they were actually born again of the Spirit.
So there is no more filling of the Spirit as we are always filled since salvation as a testimony from God that we are saved.
Matthew 9:17 Neither do men put new wine into old bottles: else the bottles break, and the wine runneth out, and the bottles perish: but they put new wine into new bottles, and both are preserved.
You are not a leaky vessel that you need a continual filling of the Spirit.
John 6:35 And Jesus said unto them, I am the bread of life: he that cometh to me shall never hunger; and he that believeth on me shall never thirst.
Jesus promised after salvation, we would never seek another filling of the Spirit as if hungering or thirsting for more of God.
John 7:38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. 39 (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)
This is how we are always filled with the Spirit since salvation as no sin can stop that flow of living waters or make Him leave us.
Ephesians 4:30 And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption.
The new reality in Christ should settle in every saved believer with contentment as filled with the Spirit always as a testimony we are saved.
1 Corinthians 6:19 What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? 20 For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's.
