The resurrection of Jesus Christ was one of the main points of early Christian preaching, it was shown to be in accordance with old testament hope and a demonstration of the claim that this Jesus is the Messiah. The resurrection they proclaimed was that Jesus was bodily raised from death, this went beyond him being alive in some sort of "otherworldly" sense, rather it was the glorification and raising again of his physical body.
In reading through the sermons in Acts and especially noting the resurrection emphasis, I noticed a point Paul made in (Acts 13:34) he says "the fact that God raised him from the dead, never to decay, is stated in these words: "I will give you the holy and sure blessings promised to David". Paul is quoting from Isaiah 55 in that statement, and to me at first glance it seems a strange way to convince someone that a person was raised from death, after all it doesn't mention resurrection anywhere. Yet upon a deeper analysis of the statement the point being made is great truth, and defines not only that God "raised Jesus", but that in raising Jesus from death He has acted according to His own nature as being a God who "keeps covenant" and creates a glorious future.
The context of Isaiah 55 is God's offer of renewal, a wonderful future for Israel freed from captivity. The return from exile in verses 11-13 is pictured by the creation itself expressing joy and experiencing liberation. So it was with the promise to David, the throne had fallen and the house was desolate (Psalms 89). The prophets however saw God raising again the house of David and fulfilling His promise (Acts 15:15-17). This fulfillment had effects that would extend to all nations and a Kingdom that would fill the earth. God reaches to humanity to bring us out of our displacement caused by evil and restore us to Himself.
God seeks the healing of His creation, (Hosea 6:1-3) "Come, and let us return unto the Lord: for he hath torn, and he will heal us; he hath smitten, and he will bind us up. After two days will he revive us: in the third day he will raise us up, and we shall live in his sight. Then shall we know, if we follow on to know the Lord: his going forth is prepared as the morning; and he shall come unto us as the rain, as the latter and former rain unto the earth". God continually comes to us to offer mercy and stir our heart to repentance. Hosea likens God's discipline and subsequent renewal as life from death and God shall be to us as the seasonal rains upon the fields, life-giving.
God shows to be able and willing to create new reality and renew life for those who seek Him. If you read in Ezekiel chapters 33-37 you see a cycle, God punishes the waywardness of Judah and condemns the shepherds who should have watched over the people. Yet God promises to give them a true Shepherd, his servant David, God says he will bring them back from the nations of captivity and restore them to the land. Moreover he says in chapter 37 that the renewal of Judah and Israel as one kingdom will be as life from death, dry bones restored to life, and his servant David to be their King.
Jeremiah lived and prophesied during some of the bleakest of times in Judah's history, right up until Jerusalem was destroyed by the Babylonians. Again however we see the newness that God promises amid the darkest hours, read chapters 31-33. In chapter 32 Jeremiah is a prisoner and the fate of the city is assured yet God commands Jeremiah to buy a piece of property in Judah. Why buy something you never will receive. Buying property in a place that is about to be overrun by foreign invaders seems futile and a waste at the least. This transaction however was to be a signpost of the future God would restore them and create a new future.
This brings us back to Paul's usage of Isaiah's prophecy in (Acts 13) to support his claim of the Messiah being raised from the tomb. For one God had fulfilled the Davidic promise, even if it was in the most unlikely way, would that be unusual for God? God shows his power time and again through what we consider weak (Luke 1:52). What I hope we grasp however is that Jesus being raised from death not only says that he is Lord, but it is also a "signpost" for us, pointing to a glorious future and new reality. The resurrection of Jesus says death will not have the last word, God's future has broken into the present by raising Jesus. Even though, as in Jeremiah's time, all the data seems to indicate otherwise; God will heal his creation and reverse death.
Our "newness of life" begins in our baptism into Christ (Romans 6:1-3). Our baptism itself is a picture Paul says of Jesus being crucified and raised again, and we enter that, by that action. Look beyond the circumstances that may surround and allow God's kingdom to break into this world through you now.