Among those 120 who waited in Jerusalem and received the fulfilling of Father God's promise were Peter, John, James, Matthew and Mary, the mother of Jesus. All of them obeyed, wanted, waited and received the baptism of the Holy Spirit and spoke with other tongues. Also, the apostle Paul, the one who wrote more than 1/3 of the New Testament, was baptized with the Holy Spirit, even before being baptized in water (Acts 9:16-17).
Ephesians 1:13-14 “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, who is the guarantee of our inheritance until the redemption of the purchased possession, to the praise of His glory.”
When someone hears and believes the truth of the Gospel, they are “sealed” by the Holy Spirit. Being sealed is the proof that the sealed object belongs to the owner of the seal. This “seal of the Holy Spirit” is actually the down-payment, the guaranty of the sealed person's “contract” with God, through Jesus Christ, by which they are saved and inherit the eternal life, by becoming part of the body of Christ, the Church. As long as the person respects the contract terms, they belong to Jesus and no person or thing can change that.
John 10:27-28 “My sheep hear My voice, and I know them, and they follow Me. And I give them eternal life, and they shall never perish; neither shall anyone snatch them out of My hand.”
When we were born-again, we received just a small measure of the Holy Spirit. That is why the joy of salvation lasts for a limited period of time, and is influenced by many factors such as: how sold out to Jesus we are, how much time we spend with our heavenly Father in prayer and bible study, how spirit filled the church or group of believers are that we are a part of, how hungry we are for more of God etc.
Sadly, there are many Christians that never wanted or asked to receive the baptism of the Holy Spirit; never realizing their need and importance of this baptism for their joy to be complete and to be able to keep renewing it, by having fellowship with the Holy Spirit. As a result they live with the memory of the great joy they had when they were born-again and never enter into the fullness of joy, power and intensity that the Holy Spirit can bring.
I heard many say things like: “When we were born-again as we received Jesus as our Lord and Savior, we also received the Holy Spirit, because only through Him could we come to Jesus. So we received all of the Holy Spirit at salvation."
Can this be true? I personally know for certain that the experience of being born-again is not the same as the experience of receiving the baptism of the Holy Spirit. As a matter of fact, there was quite some time that passed between the two. Both events can only happen with the participation of the Holy Spirit. When a person becomes born-again, the Holy Spirit enters into their heart and from the inside starts the transformation process that will be visible from the outside, as the person's life changes. When a person is baptized with the Holy Spirit, the Holy Spirit is poured out by God, from above, upon the person, until the person is completely covered in His presence, as a water-fall drenches anyone who stands under it. The original word for baptism is “baptisma” and it means: immersion, sinking, completely surrounding. The amount of the presence of the Holy Spirit and the effects He initiates for the changes and results in the baptized person are way more significant than at the moment of salvation and so much that they cannot be ignored by the one who receives Him or by those around the person who is baptized with the Holy Spirit. We see that happening in all the baptisms from the book of Acts.
You may read more here: “Baptism of the Holy Spirit”