“G-d, You are mighty forever, You resurrect the dead.”
One of the names of this blessing is Techi’at Hameitim (the resurrection of the dead). This topic is its main theme — it is mentioned several times throughout the blessing — and is explained by the commentators in a number of different ways.
The different explanations of Techi’at Hameitim
1) In the purest (simplest) sense, the resurrection of the dead refers to an event that will take place in the end of days after the Mashiach’s arrival. The belief in this idea is, accordingly, one of the principles of our faith, with its source in the Torah as well as the other books of the Prophets.
2) One who is miraculously healed from a sure-death situation can also be compared to being revived from the dead, although not in the purest sense.
3) Sleep is considered a “mini-death.” Therefore, when one awakes from sleep it is considered a mini-resurrection. This comparison should not be looked at as trivial, for if it were not for the fact that G-d restores our souls to us each morning we would not wake up at all! The fact that this great miracle happens day after day makes us desensitized, and we therefore take it for granted. The truth is that every morning we are considered to be a new creation, as it is written (Eicha 3:23): “(We are) new every morning.” (See Midrash Rabba 3, section 8, on this verse.)
4) Our Sages have taught that a wicked person (rasha), who disconnects himself from G-d through his negative actions, is considered as “dead” even during his lifetime. When, however, he repents of his evil ways ― i.e., he does teshuva ― it's as though he has been brought back to life since the righteous who cling to G-d are alive in this world as well as in the next.
5) The resurrection of the dead can also be a reference to reincarnation, a concept which is taught in Kabbala. When the soul of someone who has died has not fulfilled its mission, because of sins committed or because of a lack of performance of positive commands, it may be given another chance to earn its true place in the World-to-Come by descending into this world in another body.
6) Rainfall is compared to the resurrection of the dead since rain gives life to the world. Without it, all of existence would perish.
7) A poor person is likened to a dead person (Talmud). When G-d raises him up to a position of wealth it is as if he has been revived.