This is Chapter 13 of "Jesus Christ our Lord Basic Points of the Gospel" by Fr Maximos Moschos of Mount Athos, translated from the Greek by Fr Peter A. Chamberas.
It is characteristic and remarkable that St. John the Baptist preached repentance because the Kingdom of God is coming (Mt. 3:2.). Our Lord also preached repentance and belief in the Gospel because the Kingdom of God is at hand; it has come (Mt. 4: l7; Mk. 1:15). Following the commission of Christ, the Disciples also preached repentance (Lk.6:12.) precisely because the Kingdom has come (Mt. 10:7). And at the end of his public ministry, Christ directed the Disciples to preach in His name repentance and forgiveness of sins (Lk.24:47). That is, the basic point of the preaching centred around the Kingdom of God, and all the details had to do with how this Kingdom could prevail. The Kingdom of God has no end (Lk. l:33); it will be given to all those who would observe its prerequisites (Mt. 21: 43). One enters the Kingdom of God after a struggle (Mt.1 1:12) and it comes quietly into the heart of the believer (Lk.17:20-21). Some of the prerequisites for entrance into the Kingdom of God are: doing the will of God (Mt. 7:21), spiritual rebirth through faith and baptism (Jn. 3: 3-8), humility (Mt.18:3), a child-like attitude (Mt.19:14), patience in persecution (Mt. 5:10), sacrifice of possessions (Mt. 13:44-46), a greater perfection than that of the Pharisees (Mt. 5:20), love for the needy brethren (Mt. 25: 34-36), and finally seeking after the Kingdom of God (Mt. 6:33). The Kingdom of God is also called eternal life, which is the blessed and thrice-happy life in Paradise near our heavenly Father, but which begins in part from here and now. It is noted here that certain words have a double meaning, a literal and a metaphorical meaning. There are those people who are bodily dead and those who are spiritually dead (Lk. 9:60). There is the physical death, but also the spiritual death, which is the result of sin and the carnal mind (1 Cor. 15:56; Rom.8:6). There is also the natural life, such as that of the animals, and the spiritual life that comes as an added gift of God (Jn. 5:40; 6:53). He who believes in the Lord and keeps His Word will go from death to life and will never see spiritual death (Jn. 5:24; 8:5 l). Our Lord is the Resurrection and the Life (Jn. 11:25). He gives the eternal life (Jn. 10: 28). His words are truth and life, and they guide us to eternal life (Jn. 6: 68). The obedience to His will brings us to eternal life (Jn. 12:50). Also, He who receives Holy Communion, that is, eats and drinks Christ through the Holy Eucharist, has eternal life (Jn. 6:54). He who believes in Christ has eternal life, and he who does not believe has the wrath of God (Jn. 3:36). Eternal life is the knowledge of God, which we acquire through faith, virtue and experience of the divine blessings (Jn. 17:3).
The Kingdom of Heaven however will be preceded by other significant events, such as the general Judgment, the Second Coming or Parousia of Christ, and other fearful events, such as the appearance of the Antichrist. Whatever is to take place just before the end of this age and whatever is to follow this end, we refer to as the "Last Things", and the study of these events is called "Eschatology". Among the many things referred to in the New Testament about the last things there is also the following information contained in the four gospels.
The Second Coming of the Lord will be preceded by the "signs of the times", certain signs which we are obliged to observe carefully and to prepare ourselves, increasing our faith and our spiritual struggles. Many people observe the natural phenomena and predict the changes of the weather, while neglecting the signs which usher in the end of the world. Such people will hear the indicting word of the Lord, for they know how to interpret the appearance of the sky, but give no attention to the signs of the times (Mt.16:1-3; Lk.12:54-56). One day the Disciples approached the Lord and asked Him, what will be the sign of His Parousia and the end of the world, and when will this take place." And Jesus began to teach them: "Take heed that no one leads you astray. For many will come in my name, saying, "I am the Christ," and they will lead many astray. And you will hear of wars and rumours of wars; see that you are not alarmed; for this must take place, but the end is not yet. For nation will rise against nation, and kingdom against kingdom, and there will be famines and earthquakes in various places: all this is but the beginning of the birth-pangs" (Mt. 24:4-8; Lk. 13:5-9; Lk. 21:8-11). Also, before these things take place, Jesus taught that the believers will suffer persecutions. He said: You will be delivered over to synagogues and prisons; you will be beaten and will stand before governors and kings, who will condemn you for calling upon the name of the Lord. But this will be an opportunity to bear testimony for Christ that will be heard by your persecutors and by all the nations. Moreover, the gospel must first be preached to all the nations. And when you are delivered up for trial by your persecutors, do not prepare an apology, what you will say. At that time you will be given utterance by the Holy Spirit, and no one will be able to resist you or to rebut your words. You will not be persecuted only by strangers, but also by parents and brothers; by relatives and friends. The father will deliver his child, and the children will rebel against the parents, and some of those delivered will be killed. Everyone will hate you because you are my disciples. Then many will be scandalised, and one will hate the other. Many false prophets will appear to lead many astray. The love of the many will become cold because lawlessness will prevail. And if I do not allow it not even a hair on your head will be disturbed. He who endures to the end will be saved (Mt. 24: 9-14; 10:17-22; Mk. 13: 9-13; Lk. 21: 12-19; l 2: 11-12). When you see the desolating sacrilege, that hateful abomination which the Prophet Daniel spoke about, that is, the Antichrist, sitting on the holy place of the temple in Jerusalem, then you should know that there will be a great tribulation, such as has not been from the beginning of the world until now. And if those days had not been shortened, no human being would be saved. But for the sake of the elect those days will be shortened. Then if any one says to you, 'Here is Christ!' or 'There he is!' do not believe it. Many false Christs and false prophets will arise and show great signs and wonders, so as to lead astray, if possible, even the elect. I have told you these things beforehand to prepare yourselves and to be vigilant. If they tell you, 'Christ is in the desert,' do not go out there to meet him; if they tell you, 'He is in the inner rooms,' do not believe it. For as the lightning comes from the east and shines as far as the west, so will be the coming of the Son of man. When the corruption of the world reaches is climax, then the angels of punishment will come down like eagles upon their prey (Mt. 24:15-28; Mk. 13: 14-23; Lk. 21: 20-24; 17: 23-24, 37; these prophecies also refer to the destruction of Jerusalem by the Roman General Titus in 70AD). Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven. And there will be great suffering and confusion among the nations of the earth, not knowing how to protect themselves. Men will, faint and lose their senses from fear and the anticipation of the evils that will befall the world.
After all this, the form of the world will change and the entire universe will be renewed. And then His sign will appear in the sky, that is, the Cross. Then all the nations of the earth who did not believe in Christ will mourn, and will see the Son of man coming on the clouds of heaven with power and great glory. And He will send out his angels with a loud trumpet call, and they will gather his elect from the four regions of the earth. As the fig tree becomes tender and puts forth its leaves, and you know that summer is near, so also when you see all these signs taking place, know that the end is near. Heaven and earth that seem so steadfast and permanent will pass away and be no more, but my words will not pass away but be fulfilled completely (Mt. 24: 29-35; Mk.13: 24-31; Lk. 21: 25-33). When exactly all these things take place is not something that is beneficial for you know. What is important is to be vigilant, to be prepared, to be always ready, because the end will come suddenly at a time when you will not know it beforehand. Be vigilant therefore and do not allow your souls to become heavy and indolent with prodigality, neglecting the work of the spiritual life, and be not so preoccupied with the cares of this life that the coming of the Son of man catches you by surprise, as if in a trap. You must pray at every hour and every instant, beseeching God for grace and power to be worthy to escape without harm from these catastrophic future events, and thus to stand before Him without fear and condemnation. The Second Coming of Christ will take place as did the great flood in the time of Noah. Then people were eating and drinking and carrying on their normal way of life until Noah entered the ark and the flood came and swept everyone away. The same thing happened with the people of Sodom and Gomorrah. They were eating and drinking, buying and selling, and when Lot left the city, fire and brimstone fell from the sky and destroyed that city and all its people. Therefore you must watch and be ready for the Son of man will come at a time when you do not expect it. You must always be ready. At that time every one will be caught wherever and however he or she is (Mt. 24:36-44; Mk.13: 32-35; Lk. 21:34-36; 17:26-36; 12:39-40). Moreover, do not be like that foolish servant who neglected his duties and abused his fellow servants, thinking that the Lord is absent and will not be coming soon (Mt. 24: 45-51; Lk. l2: 41-46). Also, do not resemble the foolish virgins who were not prepared to receive the Lord with lighted lamps Mt. 25:1-l3; Lk. 12:35-38; 13:25-28; 12:40). Do not follow the example of the other foolish servant who hid his one talent in the earth, but rather follow the example of the other servants who developed their talents and multiplied them (Mt. 25:14-30, Lk.19:11-27). The Lord made it clear that at the General Judgment He will separate all mankind as the shepherd separates the sheep from the goats. And this separation will be made on the basis of the good that each person has done for others (Mt. 25:31-46; 16:27). Finally, as Christians we are called to be ever well girded and ready for spiritual action, and our lamps to be always lit and shining brightly (Lk.12:35).