Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed -- in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised incorruptible, and we shall be changed. For this corruptible must put on incorruption, and this mortal must put on immortality. So when this corruptible has put on incorruption, and this mortal has put on immortality, then shall be brought to pass the saying that is written: "Death is swallowed up in victory." "O Death, where is your sting? O Hades, where is your victory?" The sting of death is sin, and the strength of sin is the law. But thanks be to God, who gives us the victory through our Lord Jesus Christ. Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your labor is not in vain in the Lord.
1st Letter to the Corinthians, 15: 51-58
If then you were raised with Christ, seek those things which are above, where Christ is, sitting at the right hand of God. Set your mind on things above, not on things on the earth. For you died, and your life is hidden with Christ in God. When Christ who is our life appears, then you also will appear with Him in glory.
Letter to the Colossians 3:1-4
St Anthony the Great (ca. 330 ad)
Life is the union and conjunction of  the mind,  the soul.  and the body. Death, on the other hand, is not the destruction of these conjoined things, but the dissolution of their union. For by God we are preserved after the disolution, too.
Mortal beings are sorry because they know in advance that they will die. Immortality, being good, comes to the holy soul. Mortality, on the other hand, comes to the foolish and wretched soul.
Paschal Troparion (ca 500 ad)
Christ is risen from the dead,Trampling down death by death, And upon those in the tombs, Bestowing life!
In the year AD 302, Diocletian issued an edict that every Christian soldier in the army should be arrested and every other soldier should offer a sacrifice to the Roman gods of the time. However George objected and with the courage of his faith approached the Emperor and ruler. Diocletian was upset, not wanting to lose his best tribune and the son of his best official, Gerontius. George loudly renounced the Emperor's edict, and in front of his fellow soldiers and Tribunes he claimed himself to be a Christian and declared his worship of Jesus Christ. Diocletian attempted to convert George, even offering gifts of land, money and slaves if he made a sacrifice to the Roman gods. The Emperor made many offers, but George never accepted. Recognizing the futility of his efforts, Diocletian was left with no choice but to have him executed for his refusal.
Fr. John Romaindes (1955 ad)
St. Paul clearly says that "the sting of death is sin," that "sin reigned in death," and that death is "the last enemy that shall be destroyed." In his epistles, he is especially inspired when he is speaking about the victory of Christ over death and corruption. It would be highly illogical to try to interpret Pauline thought with the presuppositions (1) that death is normal or (2) that at most, it is the outcome of a juridical decision of God to punish the whole human race for one sin, (3) that happiness is the ultimate destiny of man, and (4) that the soul is immaterial, naturally immortal and directly created by God at conception and is therefore normal and pure of defects (Roman scholasticism). The Pauline doctrine of man's inability to do the good which he is capable of acknowledging according to the "inner man" can be understood only if one takes seriously the power of death and corruption in the flesh, which makes it impossible for man to live according to his original destiny.
The moralistic problem raised by St. Augustine concerning the transmission of death to the descendants of Adam as punishment for the one original transgression is foreign to Paul's thoughts. The death of each man cannot be considered the outcome of personal guilt. St. Paul is not thinking as a philosophical moralist looking for the cause of the fall of humanity and creation in the breaking of objective rules of good behavior, which demands punishment from a God whose justice is in the image of the justice of this world. Paul is clearly thinking of the fall in terms of a personalistic warfare between God and Satan, in which Satan is not obliged to follow any sort of moral rules if he can help it. It is for this reason that St. Paul can say that the serpent "deceived Eve" and that "Adam was not deceived, but the woman being deceived was in the transgression." Man was not punished by God, but taken captive by the devil.
It is only when one understands the meaning of death and its consequences that one can understand the life of the ancient Church, and especially its attitude toward martyrdom. Being already dead to the world in baptism, and having their life hidden with Christ in God, Christians could not falter in the face of death. They were already dead, and yet living in Christ. To be afraid of death was to be still under the power of the devil--II Timothy 1:7: "For God hath not given us the spirit of fear, but of power, and of love, and of sound mind." In trying to convince the Roman Christians not to hinder his martyrdom, St. Ignatius wrote: "The prince of this world would fain carry me away, and corrupt my disposition toward God. Let none of you therefore, who are in Rome, help him." The Cyprianic controversy over the fallen during times of persecution was violent, because the Church understood that it was a contradiction to die in baptism and then to deny Christ for fear of death and torture.