"Last days" is indeed lacking in specificity...meaning that there is no number of days given, nor is there a designated beginning and end given to us in direct reference. If you were living 3000 years ago, you too would say that the time of Christ's coming and the Tribulation period, etc., are all in the last days. It's simply a way of referring to period across the entire span of this earth's timeline.
I would offer. Lasts days is simply another way to say “walk by faith” or acording to the understanding of God not seen . The period of time by which all of mankind Jew and Gentile could hear the understanding having been empowered to walk by faith (receive the understanding of God not seen) came into effect when Peter preached the word and 3000 sons of God were born again from above. The promise of Joel had come.
The tribulation which was caused by gospel it as it is written. . . it rightfully divided creating new creatures as sons of God . It is still perfectly working in the heart of born again mankind. We are still dying under the Sun. There will be no dying in the new heaven and earth to come. That corupted whole creation all the rudments will disaper in the judgemnt fire.
Remember as sons of God born again mankind is not what we will be when we receive the new incoruptible bodies .it would appear they will be niether Jew nor gentile male or female 'She is reconnized as Christ bride.
The glory of creation before God corrupted shown in a couple of Old Testament parables below. . i His glory departed and some of the beasts became eaters of flesh and blood. Death began carrying out the promise . . .Don’t eat . . You will die . . Mark my word.
The parables below reads. . .
Isaiah 11:5-7 King James Version (KJV) And righteousness shall be the girdle of his loins, and faithfulness the girdle of his reins. The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatling together; and a little child shall lead them. And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox.
In the other parable the serpents meat or the false gospel of . . . You shall surely not die it will not be heard . The former things will not be remembered or ever come to mind. It’s the end of time under the Sun. The temporal use of the Sun and Moon had served there temporal purpose .The glory is restored no temple no more night .
Isaiah 65:24-25 King James Version (KJV) And it shall come to pass, that before they call, I will answer; and while they are yet speaking, I will hear. The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust shall be the serpent's meat. They shall not hurt nor destroy in all my holy mountain, saith the Lord.
Serpents meat . The Lord’s way of saying . . hit the road, eat dust