Acts 7:48 is followed by V.49 which is a quotation from Is. 66, where it reads thus- "Thus says the Lord: Heaven is my throne and earth is my footstool. Where is the house that you will build for me? And where is the place of my rest? For all these things my hands has made. And all those things exist, says the lord. But on this one I will look on him who is poor and of a contrite spirit, who trembles at my word" (W 1-2).
Here the prophet is lashing against the institutionalization of religion. People give utmost importance and attach too much sanctity to the temples, but forget that it is their own persons, their own hearts that God wants to dwell in. If God is given choice to select between a temple and a person who is poor and of a contrite heart, He will certainly prefer the latter. However, the acceptance of the latter does not necessarily involve the rejection of the former. In poetic language, when we want to emphasis one point, we will exaggerate it at the cost of probably, the next important point. Hence building of temple or temple worship is not rejected by Is. 66:1-2 or Acts 7:48.
A temple has no sanctity in itself. It becomes sacred only when the lord God chooses it to put His name for His habitation (Deut 12:5), only when the Glory of the lord fills it (Ez. 43:5). Solomon who built the first temple to Yahweh was aware of his limitations when he expressed his doubt, but will God indeed dwell on earth? Behold the heaven and heaven of heavens cannot contain you. How much less this temple which I have built!" I King 8:27 Yet Solomon hoped that God will hear the prayer and supplication of His people and forgive them, when they pray toward this place (V. 30). After the consecration of the temple for worship, Solomon blessed the congregation gathered there saying, "May the lord our God, be with us, as He was with our fathers, may he not leave to Himself, to walk in all His ways, and to keep His commandments and His statutes, and His judgments, which he commanded our fathers" (VV. 57-58). Hence temple worship is not a substitute for righteous living, rather an inducement to keep our heart poor and contrite, to walk in all His ways and to keep His commandments. Localization of God's presence is an incentive for our spiritual life.
Coming to Acts 7:48, it is Stephen who speaks out this sentence (which resembles I kgs. 8:27) as he goes on criticizing the Jewish Council which gave undue importance to temple and law, and in the process destroyed the real temple (Jesus) and resisted the spirit. "You stiff-necked and uncircumcised in heart and ears! You always resist the Holy Spirit (Acts 7:51). Though the Jews received the law, they remained stiff-necked, rebellious and often disobeyed God (V. 53). Though they insisted on all the stipulations given by God including Circumcisions they were not ready to be circumcised in heart and ears. They were not willing to listen to the word of God and inscribe them in their hearts and live accordingly. It is the circumcised ears and hearts that the Lord requires, not so much the temple made of human hands. This is the essence of what Stephen says in Acts 7:48-51. Since the Jews discarded the circumcision of heart and ears and resisted the Holy Spirit, they could not become the temples of God. Nor could they accept Jesus, as the real temple, the Glory of God (In. 2:19-21 Cf. V.55). So for the sake of a temple which God already had abandoned, and for the sake of a law which they are not obeying, they put to death a real temple (1 Cor. 3:16,17); 6-19), and a real follower of the fullness of law. This is what happens when fanatics get the upper hand in any religion.
Jesus himself has strongly reacted to this corruption of religions and condemns the Pharisees and Seducees for making religion a hypocrisy (Mk. 23). He tried to cleanse Jerusalem Temple, His Father's House, a House of Prayer, when it was turned to a "den of thieves (21 :12-13). But the god-fathers of the polluted religion took it in an amusing mood. So Jesus had to comment over Jerusalem "0 Jerusalem, Jerusalem, the one who kills the prophets and stones those who are sent to her! How often have I wanted to gather your children together, as a hen gathers her chicks under her wings, but you were not willing (Mt. 23:37). About the temple he had to say, assured by, I say to you, not one stone shall be left here upon another, that shall not be thrown down (Mt. 24:2).
The new Jerusalem Temple is the risen body of Jesus (In. 2:19.21) the Church (1 Cor. 12:27 Eph. 5:30). Here the worship is done in spirit and truth (In. 4:23). However this worship is done in the community of faithful. Hence we should not forsake the assembling of ourselves together, but exhort one another, so much the more as we see the Day of the Lord approaching (Heb. 10:25). For this, and for braking of the bread and keeping it, we need a common place alias church. Simple constructions are quite sufficient for our use.