Judge none blessed before his death: for a man shall be known in his children.
Read Chapter 11
John Cassian
AD 435
But that even the powers above are, as we said, subject to change is shown by those who fell from their ranks through the fault of a corrupt will. This is why we should not think that the nature of those who remain in the blessed condition in which they were created is unchangeable, simply because they were not similarly led astray to choose the worse part. For it is one thing to have a nature incapable of change and another thing for a person through the efforts of his virtue, and by guarding what is good through the grace of the unchangeable God, to be kept from change. For everything that is secured or preserved by care can also be lost by carelessness. And so we read, "Call no one happy before his death," because so long as an individual is still engaged in the struggle, and if I may use the expression, still wrestling"even though he generally conquers and carries off many prizes of victory"yet he can never be free from fear and from the suspicion of an uncertain outcome. And there...
Death, previously abhorred and hated, is now the object of praise and declared blessed. What at one time procured pain and sadness, tears and melancholy, now appears as a source of joy and feasting. All the servants of God enjoy a blessed death because the end of their lives bears the security of being welcomed by God. In fact, they become perfect, and this perfection renders them blessed, giving them the solidity of virtue, as the oracle affirms, "Do not judge a person blessed before his death." - "Homily on the Dormition 1.12"