The answer from God’s word:
At the time Jesus’ work was the redemption of all mankind. The sins of all who believed in Him were forgiven; as long as you believed in Him, He would redeem you; if you believed in Him, you were no longer a sinner, you were relieved of your sins. This is what it meant to be saved, and to be justified by faith. Yet in those who believed, there remained that which was rebellious and opposed God, and which still had to be slowly removed. Salvation did not mean man had been completely gained by Jesus, but that man was no longer of sin, that he had been forgiven his sins: Provided you believed, you would never more be of sin. … Jesus did not come to perfect and gain man, but to do one stage of work: bringing forth the gospel of the kingdom of heaven and completing the work of the crucifixion—and so once Jesus was crucified, His work came to a complete end. But in the current stage—the work of conquest—more words must be spoken, more work must be done, and there must be many processes. So too must the mysteries of the work of Jesus and Jehovah be revealed, so that all people may have understanding and clarity in their belief, for this is the work of the last days, and the last days are the end of God’s work, the time of this work’s conclusion. This stage of work will elucidate for you the law of Jehovah and the redemption of Jesus, and is principally so that you may understand the entire work of God’s six-thousand-year management plan, and appreciate all the significance and substance of this six-thousand-year management plan, and understand the purpose of all the work done by Jesus and the words He spoke, and even your blind credence in and adoration of the Bible. All this it will allow you to perceive. You will come to understand both the work done by Jesus, and the work of God today; you will understand and behold all of the truth, the life, and the way. In the stage of work done by Jesus, why did Jesus depart without concluding God’s work? Because the stage of Jesus’ work was not the work of conclusion. When He was nailed to the cross, the words that He had spoken also came to an end; after His crucifixion, His work completely finished. The current stage is different: Only after the words are spoken to the end and God’s entire work is concluded will His work have finished. During Jesus’ stage of work, there were many words that remained unsaid, or which were not fully articulated. Yet Jesus cared not what He did or did not say, for His ministry was not a ministry of words, and so after He was nailed to the cross He departed. That stage of work was chiefly for the sake of the crucifixion, and is unlike the stage today. This stage of work is principally for the sake of completion, of clearing up, and of bringing all work to a conclusion. If the words are not spoken to their very end, there will be no way of concluding this work, for in this stage of work all work is brought to an end and accomplished using words. At the time, Jesus did much work that was incomprehensible to man. He departed quietly, and today there are still many who do not understand His words, whose understanding is erroneous yet still believed by them to be correct, who do not know that they are wrong. In the end, this current stage will bring God’s work to a complete end, and will provide its conclusion. All will come to understand and know of God’s management plan. The conceptions within man, his intentions, his erroneous understanding, his conceptions toward the work of Jehovah and Jesus, his views about the Gentiles, and all his deviation and errors will be corrected. And man will understand all the right paths of life, and all the work done by God, and the entire truth. When that happens, this stage of work will come to an end.
from “The Vision of God’s Work (2)” in The Word Appears in the Flesh
… after the work of Jesus ended, God still continued His work for the next age, because the entire management of God is always progressing forward. When the old age passes, it will be replaced by a new age, and once the old work has been completed, a new work will continue the management of God. This incarnation is God’s second incarnation following the completion of Jesus’ work. Of course, this incarnation does not occur independently, but is the third stage of work after the Age of Law and the Age of Grace. … When Jesus came into the world of man, He brought the Age of Grace and ended the Age of Law. During the last days, God once more became flesh, and when He became flesh this time, He ended the Age of Grace and brought the Age of Kingdom. All those who accept the second incarnation of God will be led into the Age of Kingdom, and be able to personally accept the guidance of God. Though Jesus did much work among man, He only completed the redemption of all mankind and became man’s sin offering, and did not rid man of all his corrupt disposition. Fully saving man from the influence of Satan not only required Jesus to take on the sins of man as the sin offering, but also required God to do greater work to completely rid man of his disposition, which has been corrupted by Satan. And so, after man was forgiven his sins, God has returned to flesh to lead man into the new age, and begun the work of chastisement and judgment, and this work has brought man into a higher realm. All those who submit under His dominion shall enjoy higher truth and receive greater blessings. They shall truly live in the light, and shall gain the truth, the way, and the life.
If people remain in the Age of Grace, then they shall never be free of their corrupt disposition, let alone know the inherent disposition of God. If people always live among an abundance of grace but are without the way of life that allows them to know God and satisfy God, then they shall never truly gain Him though they believe in Him. … if you cling to views of the past, and reject or deny the fact of the second incarnation of God, then you shall remain empty-handed and acquire nothing, and ultimately be guilty of opposing God. Those who obey the truth and submit to the work of God shall come under the name of the second incarnate God—the Almighty. They will be able to accept the personal guidance of God, and shall acquire more and higher truth and receive the real human life. They shall behold the vision that people of the past have never seen….
… when God becomes flesh this time, His work is to express His disposition, primarily through chastisement and judgment. Using this as the foundation, He brings more truth to man, shows more ways of practice, and so achieves His objective of conquering man and saving man from his corrupt disposition. This is what lies behind the work of God in the Age of Kingdom.
from Preface to The Word Appears in the Flesh
The Holy Spirit works in accordance with the age, not just at will or according to set rules. The age has changed, and a new age must bring with it new work. This is true of every stage of work, and so His work is never repeated. In the Age of Grace, Jesus did much of that work, such as healing sickness, casting out demons, laying His hands upon man to pray for man, and blessing man. However, to continue to do so would serve no purpose in the present day. The Holy Spirit worked in that way at the time, for it was the Age of Grace, and man was shown enough grace for enjoyment. Man did not have to pay any price and could receive grace as long as he had faith. All were treated very graciously. Now, the age has changed, and the work of God has progressed further; through His chastisement and judgment, the rebelliousness of man and the unclean things within man will be cast away. As it was the stage of redemption, God had to do such work, showing man enough grace for man to enjoy, so that man could be redeemed from sin, and through grace be forgiven their sins. This stage is done to reveal the iniquities within man through chastisement, judgment, the smiting of words, as well as the discipline and revelation of words, so that they may afterward be saved. This is work more in-depth than redemption. In the Age of Grace, man enjoyed enough grace and has already experienced this grace, and so it is no longer to be enjoyed by man. Such work is now out-of-date and is no longer to be done. Now, man is saved through judgment by the word. After man is judged, chastised and refined, his disposition is thereby changed. Is this not because of the words I have spoken? Each stage of work is done in line with the progress of all mankind and with the age. All work has its significance; it is done for the final salvation, for mankind to have a good destination in the future, and for man to be divided according to their kind in the end.
The work in the last days is to speak words. Great changes can be effected in man through the words. The changes now effected in these people on acceptance of these words are much greater than that of people in the Age of Grace on acceptance of those signs and wonders. For, in the Age of Grace, the demons went away from man with the laying on of hands and prayer, but the corrupt dispositions within man still remained. Man was healed of his sickness and forgiven his sins, but the work for just how the corrupt satanic dispositions within man could be cast away was not done in him. Man was only saved and forgiven his sins for his faith, but the sinful nature of man was not taken away and still remained within him. The sins of man were forgiven through God incarnate, but it does not mean that man has no sin within him. The sins of man could be forgiven through the sin offering, but man has been unable to resolve the issue of just how he can no longer sin and how his sinful nature can be cast away completely and be transformed. The sins of man were forgiven because of the work of God’s crucifixion, but man continued to live in the old, corrupt satanic disposition. As such, man must be completely saved from the corrupt satanic disposition so that the sinful nature of man is completely cast away and never again develops, thus allowing the disposition of man to be changed. This requires man to understand the path of growth in life, the way of life, and the way to change his disposition. It also needs man to act in accordance with this path so that the disposition of man can gradually be changed and he can live under the shining of the light, and that he can do all things in accord with the will of God, cast away the corrupt satanic disposition, and break free from Satan’s influence of darkness, thereby emerging fully from sin. Only then will man receive complete salvation. When Jesus was doing His work, man’s knowledge of Him was still vague and unclear. Man always believed that He was the son of David and proclaimed Him to be a great prophet and the benevolent Lord who redeemed man’s sins. Some, based on faith, became healed just by touching the edge of His garment; the blind could see and even the dead could be restored to life. However, man could not discover the corrupt satanic disposition deeply rooted within him and neither did man know how to cast it away. Man received much grace, such as the peace and happiness of the flesh, the blessing of the entire family upon the faith of one, and the healing of sicknesses, and so on. The rest were the good deeds of man and their godly appearance; if man could live based on such, he was considered a good believer. Only such believers could enter heaven after death, which means that they were saved. But, in their lifetime, they did not understand at all the way of life. They merely committed sins, then made confession in a constant cycle without any path toward a changed disposition; such was the condition of man in the Age of Grace. Has man received complete salvation? No! Therefore, after that stage was complete, there is still the work of judgment and chastisement. This stage makes man pure through the word so as to give man a path to follow. This stage would not be fruitful or meaningful if it continued with the casting out of demons, for the sinful nature of man would not be cast away and man would only stop upon the forgiveness of sins. Through the sin offering, man has been forgiven his sins, for the work of the crucifixion has already come to an end and God has prevailed over Satan. But the corrupt disposition of man still remains within them and man can still sin and resist God; God has not gained mankind. That is why in this stage of work God uses the word to reveal the corrupt disposition of man and asks man to practice in accordance with the right path. This stage is more meaningful than the previous one and more fruitful as well, for now it is the word that directly supplies man’s life and enables the disposition of man to be completely renewed; it is a stage of work more thorough. Therefore, the incarnation in the last days has completed the significance of God’s incarnation and completely finished God’s management plan for the salvation of man.
from “The Mystery of the Incarnation (4)” in The Word Appears in the Flesh