Jesus became the first of many brothers, when He came out of the water of baptism, and the Holy Spirit descended on Him. In doing so, He set the example of “The Way.”
Peter declared, “repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit” (Acts 2:38).
The descent of God’s Spirit is His affirmation that we have been sanctified. The Holy Spirit is the “seal” of our salvation (Ephesians 1:13-14).
Of course, as humans we are rarely in the perfect situation where we believe, are baptized immediately, God sees our faith, and we receive the Spirit as we come up from the water. The Holy Spirit is not received automatically after baptism and is often imparted through “the laying on of hands”; see Acts 8:14–17. The Spirit of God may also descend before baptism; see Acts 10:44–47. Still today, we see the Spirit of God descending before and after baptism. And a believer may require prayer to receive the Spirit; see Luke 11:5–13.