I don't see this as saying that they ended with the death of the apostles. "Then I shall know fully" would refer to the time when Jesus returns and after the resurrection etc.
The word holy means sacred, belonging to God. The word spirit means invisible active force that produces visible results. The Greek word pneuma, from which the English words pneumatic and pneumonia come, can be translated as spirit, wind, breath, compelled mental inclination or spirit beings. The Hebrew and Greek words come from a root word meaning blow. When God grants his holy spirit to someone they accomplish his will with the aid of that force. Prophets, apostles, healing, walking on water, creating life, the universe and everything. Jesus existed in heaven in spirit form as Michael before coming to Earth. He, with God's holy spirit as Michael created the heavens and earth. (John 17:6; Colossians 1:16) The Trinity is a Babylonian teaching introduced into apostate Christianity through the influence of Greek philosophy. From Plato. Platonic.
In an event of great magnitude it isn't necessary for signs to occur except for that those witnessing those events should know from where those events come. Jesus and the apostles healing and performing other signs are for a witness only. Pentecost 33 CE, for example, was a sign that Jehovah had abandoned the Jews who had rejected the messiah and from then on supported the Christian congregation. (Acts 2:1-31) Once that had been established those sorts of events were no longer necessary to establish the church.
Jesus came to Earth to sacrifice his blood for our sins. Adam's blood had been spilled by the results of his sin. Adam had been created to live forever without sin. Satan, in effect murdered the perfect (perfect meaning having great potential) Adam, and consequently every person ever born from then on. So only Jesus' blood (without sin) could pay the ransom sacrifice for Adam's blood. Blood (life, soul) for blood. Eye for eye, tooth for tooth. Sin equals death. The meek shall inherit what? Heaven? No. The earth.
Jesus sacrifice was once for all time. He is never meant to physically return to Earth at some later date. Why would he? His presence will be felt when, as king he returns his attention to earth to deal with Satan, not to come as a man as he once did. That's over.
It is by the authority of Jesus that casting out demons works and that also continues.
The gifts of the Holy Spirit are for building up the Church and that is always needed.
1Cor 13:8 Love never fails. But where there are prophecies, they will cease; where there are tongues, they will be stilled; where there is knowledge, it will pass away. 9 For we know in part and we prophesy in part, 10 but when completeness comes, what is in part disappears. 11 When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put the ways of childhood behind me. 12 For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known.
Not always. If they did these things in part, incomplete, as a child, then when does the church mature and to what end? First of all, they don't need signs. They have faith. So, if you go to a place where they are speaking in tongues and you are a linguist, you know they are speaking gibberish. At Pentecost they spoke no language that wasn't spoken there. Today they speak in tongues to impress one another or because they are in a state of hysteria. Those that Jesus healed later died again. Jesus demonstrated the reality of a possible resurrection. Today if you see people healing it is a deception. At best the person being healed, in the excitement, briefly thinks they have been healed when they haven't.
So, if you are right and I am wrong, show me so that I may witness it. Or, is it that the world witnesses the deception and judges the congregation accordingly?
Ask yourself. What would be the wise thing for Satan to do? The originator of the lie. Either mislead the congregation as a witness for him or create the deception just as the magic practicing priests did before Moses.