This is a good and important question.  You listed four things: salvation, repentance, baptism, and the receiving of the Holy Spirit.  Let’s look at each one in their proper order. 

REPENTANCE – The definition of repent is to think differently or afterwards, i.e. reconsider (morally, feel regret). Repentance is when you begin to regret your lifestyle…the way you are living and the sins in your life. 

  • Mark 1:14-15, “Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God, And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.”
  • Luke 5:32, “I came not to call the righteous, but sinners to repentance.”

One has said that repentance is really taking God’s side against yourself.  It is seeing yourself as God sees you.  It is realizing you are a guilty sinner who must answer to God for your sins.  Both of the verses above show that true repentance will lead one to believe on the Lord Jesus Christ.  The Lord calls sinners to repentance so they might believe on Him.  As you can see…repentance comes first in this order. 

SALVATION – Salvation is the act of God when He rescues us from our sins and gives us a new life in Christ Jesus through faith in Him.  When the Lord saves us, He saves us from the PENALTY of sin, He saves us from the POWER of sin, and He will one day save us from the very PRESENCE of sin by taking us to be with Him in Heaven.

  • Acts 20:21, “Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ.”
  • 2 Corinthians 7:10, “For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death.” 
  • Romans 10:9, “That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.”

When we put our faith in the Lord Jesus Christ, we are saved.  We receive eternal life (John 3:16).  We become the children of God (John 1:12).  We are made brand new and become new creatures (2 Corinthians 5:17).

RECEIVING OF THE HOLY SPIRIT – When someone puts their faith in the Lord Jesus Christ, they are saved eternally.  At the very moment of their salvation, they are indwelt with the Holy Spirit. 

  • Ephesians 1:13, “In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise.”
  • 1 Corinthians 12:12-13, “For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ. For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.”
  • Romans 8:9, “But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.”

The indwelling of the Holy Spirit is instantaneous when we trust in the Lord Jesus Christ as our savior. The Holy Spirit is He that baptizes us into the body of Christ.  In fact, if the Holy Spirit does not dwell in a person, that person is not saved. 

BAPTISM – Water baptism is a work of the obedient believer.  The Lord desires that all believers be baptized in water, but the time between the moment of salvation and baptism can vary.  The Lord wants us to be baptized soon after we are saved as a testimony to the fact that we have died with Christ, have been buried with Him, and are risen to new life in Him.

  • Romans 6:3-4, “Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.”
  • Acts 8:36-38, “And as they went on their way, they came unto a certain water: and the eunuch said, See, here is water; what doth hinder me to be baptized? And Philip said, If thou believest with all thine heart, thou mayest. And he answered and said, I believe that Jesus Christ is the Son of God. And he commanded the chariot to stand still: and they went down both into the water, both Philip and the eunuch; and he baptized him.”

I trust these scriptures have made it clear that the order of events that you asked about are REPENTANCE, SALVATION, RECEIVING OF THE HOLY SPIRIT, AND WATER BAPTISM.  (CC)  (595.4)