On the evening after his resurrection, Jesus “breathed on them and said to them, ‘Receive the holy spirit’.” (Jn 20:22). How, then, is it possible to become filled with the Holy Spirit seven weeks later on Pentecost (Acts 2:1-4) if the disciples already received the Holy Spirit?
The first truth that emerges is that the indwelling of the Holy Spirit is not necessarily substantiated by outward manifestations. The second truth is that Jesus imparted to them what had been imparted to him when he was first baptized (Jn 1:32-33, Mk 1:10, Lk 3:22, Mt 3:16). According to John the Baptizer, “a person cannot receive even one thing unless it is given him from heaven” (Jn 3:27). Therefore, Jesus’s miracle-working power would seem to flow from the infilling of the Holy Spirit. Jesus’s power came upon him invisibly at the Jordan river, took root while in the wilderness, and thereafter grew “like a mustard seed”.
On the day of Pentecost the disciples were gathered together when there was a sensory phenomenon and they began speaking in unknown tongues. This suggests that they were not speaking languages that could be identified by them or else the text would sa h the began speaking in Phoenician, Sanskrit, etc. Only the outside observers claimed to “hear them speak in his own language” (Acts 2:6). So if the disciples uttered unidentifiable sounds, it was the anointing conveyed within the utterances which struck the spirits and minds of those witnesses to perceive the message as an intelligible thought in the language(s) which the hearers knew. Others just heard babbling and accused the disciples of drunkenness (Acts 2:13). This miracle of audition follows the predicate of Jn 12:29-30 in which human subjects perceive God’s oracles according to their spiritual receptiveness.
One takeaway here is that “speaking in tongues” is not proof of possessing the Holy Spirit within oneself. Uttering humanly unintelligible sounds simply means that one’s prayer transcends the limitations of human speech that the declarations and supplications of the Holy Spirit are just too complex to be reduced to a finite vocabulary and syntax. (1 Cor 14:14). Another takeaway is that those utterances are concealed from the agents of Hell (whether human or demonic) who have not the ability to understand what they do not possess.