Jesus is speaking of physical death when He says “though he dies”. Physical death is the end for the unbeliever, but not for the one who believes in Jesus.

“I am” = Jesus so completely holds the keys to resurrection and life that He does not say that He “gives” them, but that He “is” them. Without Jesus there is no resurrection and there is no life. There is also a hint of Jesus declaring Himself to be God by His use of the “I am” statement.

“the resurrection and the life” = These two things are bound together. As Calvin notes, “First, He calls Himself the resurrection; for restoration from death to life precedes the state of life. But the whole human race is plunged in death. Therefore, no man will possess life until he is first raised from the dead. Hence Christ teaches that He is the beginning of life. Afterwards He adds that the continuity of life is also the work of His grace.” For the dead to partake of life, they must first be raised from their death.

life = The last words of Edward the Confessor were, “Weep not, I shall not die; and as I leave the land of the dying I trust to see the blessings of the Lord in the land of the living.” (qt’d in Barclay) We have wrongly called this life the land of the living, for everyone here is dead apart from Christ.

According to Webster’s dictionary a paradox is “a statement that seems contradictory, unbelievable, absurd but that may be actually true in fact.” Jesus here gives the paradox that those who are dead shall live. This declares the great truth that physical death is not nearly as important as spiritual death. The one may last for an instant and be overcome by trusting in Jesus; the other lasts forever without hope.

“believes” = pisteuo = to be so fully persuaded that one places their trust in Him. This means that we must believe everything that Jesus says and trust Him so completely that we “stake our lives upon” Him. (Barclay)

resurrected life = involves eternal life, a new relationship with God, and a power-packed life of victory in the physical realm.

When do we receive? = Morris notes this in the following: “This transcends the Pharisaic view of a remote resurrection at the end of time. It means that the moment that a man puts his trust in Jesus he begins to experience that life of the age to come which cannot be touched by death. Jesus is bringing Martha a present power, not the promise of a future good.”

This great and new teaching about the resurrection is the whole reason that Lazarus died, that Jesus delayed in coming, and for the raising of Lazarus from the dead. But it is also a prelude of the raising of Jesus from the dead, the first-fruits of us all (1 Cor 15:20).

1 Corinthians 15:20  But Christ has indeed been raised from the dead, the firstfruits of those who have fallen asleep.