Answer: You say that the Lord promised man that He would come again to take man into the kingdom of heaven, that is for sure, because the Lord is faithful, He will invariably make good on His promises. But we need to first be clear that the Lord's coming again through incarnation in the last days to do the work of judgment is directly related to how we are raptured into the kingdom of heaven.
Relevant Words of God:
God become flesh is called Christ, and so the Christ that can give people the truth is called God. There is nothing excessive about this, for He possesses the substance of God, and possesses God’s disposition, and wisdom in His work, that are unattainable by man. Those who call themselves Christ, yet cannot do the work of God, are frauds. The real Christ is not merely the manifestation of God on earth, but also the particular flesh assumed by God as He carries out and completes His work among man. This flesh is not one that can be replaced by just any man, but one that can adequately bear God’s work on earth, and express the disposition of God, and well represent God, and provide man with life. Sooner or later, those who impersonate Christ will all fall, for although they claim to be Christ, they possess none of the substance of Christ. And so I say that the authenticity of Christ cannot be defined by man, but is answered and decided by God Himself.
from “Only Christ of the Last Days Can Give Man the Way of Eternal Life” in The Word Appears in the Flesh