Cvengr: when a Catholic in a state of grace receives Communion would you say he receives the Holy Spirit in the Host as well? And to what you wrote and adding on to my question, would we even be receiving the whole Blessed Trinity at Communion?
The indwelling of God the Holy Spirit is completely by the volition of God. The indwelling of God the Holy Spirit isn't something we feel, or necessarily experience.
This doesn't mean that other works of God, such as spiritual gifts, which are uniquely given us by God the Holy Spirit, might indeed have experiences, memory recall, emotions or feelings, or simply knowledge directly provided by Him, but the actual indwelling isn't an operation dependent upon man.
God is free to indwell us and His decision performs that action, which we also may perceive as being performed from His Grace in response to the request of the Son to the Father for the Holy Spirit to come to us.
The Holy Spirit ALWAYS glorifies the Son in this Church Age.
In a Johanine sense, we aren't saved with a regenerated human spirit on multiple occasions, but we might be forgiven of sins on multiple different occasions if we have sinned between periods of being in fellowship with Him.
In a Pauline sense, when we remain in fellowship, we do not sin, but when we do sin it is the old sin nature which we have given control of our soul when we slip out of fellowship.
Would we be receiving the whole Blessed Trinity at Communion? (Eucharist)
IMHO, A believer who turns back to God as the focus of his thinking, confessing all known and unknown sins to Him, has precisely repented (turned away from sin and back to God) and confessed (communicated to God his falling away) and then God is free and just to forgive those sins, thereby re-establishing the state of fellowship between God and believer.
When we take Communion, we are obeying the direction of Christ by taking the bread in remembrance of Him. God the Holy Spirit provides the temple for God the Son to indwell the body of the believer. That temple provided by God the Holy Spirit is associated with out thinking in our mind, a compartment of the soul. It is also associated with the human spirit, as discernible from the soul.
I can understand how a believer receiving Communion (Eucharist) is performing a religious mechanism to check that he is back in fellowship with God the Holy Spirit by repentance and confession, then might be indwelled by Christ, sharing between believers in assembly, and the Father is in Him.
John 14:20 expresses: Christ is in the Father, we as believers in fellowship are in Him, and Christ is in us. John 14:21 further continues that for those who keep His commandments, the Father and the Son love that believer, and will manifest Hiself (the Son) to that believer.
John 14:23 further describes how the Father and the Son shall abide in the believer when those commandments are obeyed.
So, yes, when we are obedient, in fellowship with Him, such as in Communion, it is accurately said that all three persons of the Godhead may be indwelling the believer.
The manifestation of that indwelling is probably better understood by studying the Shekinah Glory and its manifestation of the cloud and pillar of fire outside the Tabernacle in the Old Testament.
Shekinah is derived from the Hebrew root for "to dwell". When God dwelt in the tabernacle and among His people it was performed with a protocol maintaining and establishing Holiness. The same occurs in the Church Age, where the temple is our body and He indwells us.
The halo seen in early Church paintings over the heads of saints, might very well be associated with the indwelling of God in the believer and a manifestation of that indwelling, similar to the cloud or pillar of fire manifest the Shekinah Glory over the tabernacle in the Old Testament.