It should be noted that in Matthew 10:7-8, the Lord is addressing the twelve disciples. I don't think we can make this the basis for a general principle. It's also worth noting that the phrase "raise the dead" has been inserted into the text by the translators - no doubt accurately.
I don't want to be controversial, and I'm wary of stirring up an interminable debate. I'll answer your question though, dear brother, as best I can.
The times we live in now are not the same as those which prevailed at the beginning of the dispensation (or 'era' if some brethren prefer). Then, the Church was in outward display in unity and power. To use a simple illustration, if I were a believer in Corinth, or Ephesus, or Galatia, I would gather with every other believer in the city - the Church was in evidence. The apostle Paul could write to the Church in a place and the epistle would be delivered to the Church in that place - not a particular building, but the full complement of believers in that place. Today, if someone was to write to the Church in - say - New York, or Amsterdam, or Moscow, the messenger would ask, "Which church do you mean?". Outwardly, there's breakdown. Believers are scattered among man-made churches, or independent companies. There is no outward display of the one Church, in unity and power. That's not to say, and we must be clear about this, that divine power is diminished in any way, or that the thought of the one Church has been given up by God. Far be the thought - it could never be so. But the testimony as to there being one Church has largely been given up - many believers have turned to denominationalism or independency, both of which are equally incompatible with the truth of the one Church, the one Body. In these conditions, there aren't outward demonstrations of power for all the world to see. You might say that the Church is hidden at the moment. Is the world presently aware of there being one Church, united, powerful? It was at the beginning. It caused a great stir in the Roman world and beyond! But, is the world aware of it now? No. The worldly person doesn't believe for a moment that there's a single, unified Church. That fact is obscured, hidden from the eyes of the world - and with it, the works of power that bore witness to a Church in the world. The scripture tells us that sign gifts, such as tongues, are for unbelievers. "So that tongues are for a sign, not to those who believe, but to unbelievers; but prophecy, not to unbelievers, but to those who believe." (1 Corinthians 14:22). One might say that the time for demonstration in the sight of the world is passed, and the time of secret upbuilding is here - and that is where power is seen, felt and experienced by believers. We can trace this in the addresses to the seven Churches in Revelation 2-3. There is a word to "him that overcomes". The overcomer isn't seen in a blaze of power and glory in the world. No, the overcomer finds a hidden resource in the middle of the confusion and decline of Christendom. I don't believe that God is working in the way that He did in the early Church in terms of evident miracles attesting to the presence of the Church in the sight of the world - that's evident from the addresses to the seven Churches, and we can see the difference in conditions between Paul's first and second epistles to Timothy. But I don't for a moment believe that there has been any curtailing of power. There is infinite power and resource available to the overcomer in an evil day. "He that overcomes", and the context in which this kind of person is mentioned show us that there's much to be overcome. Obstacles, tests and trials aren't removed - they're overcome. Grace is given to meet them. The thorn in Paul's flesh wasn't taken from him, but he was given grace to bear it. That is a word for the times in which we live. As for myself, signs and wonders don't follow me, but I have a very distinct sense of the immensity of divine power. It couldn't be further from the truth to say that God is not doing anything now. His power is real and operational, and particularly suited to the time in which we are, and the conditions in which we are. The Lord didn't convey one address to seven different assemblies - He had a word for each. In that way, God has brought it what is needed at each stage of the history of the Church.
As an aside, we mustn't think that the healing of the bodies of believers is a general principle on which God operates. Paul's thorn (2 Corinthians 2:17) has already been mentioned. A brother recently referred on this forum to Timothy's stomach troubles and frequent illness, which Paul advised should be medicated with a little wine (1 Timothy 5:23) - the medicine of the day. Trophimus was left behind in Miletus sick (2 Timothy 4:20). Were Paul, Timothy and Trophimus insufficiently imbued with divine power to heal one another? Could others not have laid hands on them and healed them? These facts, recorded for us on the page of scripture, show that bodily healing is not a general principle. Healing, along with other signs, was a display of divine power and confirmed the divine authority of those who displayed it. It wasn't simply to relieve believers of discomfort, although the mercy and love of God is no doubt in it for those who got relief. I'm sure that there were many more believers sick in those days than were miraculously healed, as there are these days as well. How comforting it is that "we know that to them that love God all things work together for good" (Romans 8:28). "All things" would include illness, loss of loved ones, trials and painful exercises of all kinds. We learn the heart of God in whole new ways when we pass through these things. We learn the greatness of His love, the vastness of His wisdom, the sovereignty of His purpose, the power of His arm. Precious metals are extracted from the ore and separated from the dross in the heat of the furnace, and we all need something of the furnace heat for God to bring to fruition what He has in mind for us.