The earth is much older than 6000 years but our creation started about 6000 years ago with a literal 6 days creation
Before the six days’ work began, genesis, chapter 1 verse 2, shows us “darkness on the face of the deep;” the earth without order, and void. The very first incident described is the movement of the spirit of God “on the face of the waters” (same verse), from which it follows the earth and the waters existed before the re-organising work of 6,000 years ago began.
The earth had a history before the six days’ work, as further evident from the words addressed to Adam: “Be fruitful and multiply, and replenish the earth.”
Both the Bible and geological records show it was a history marked by upheaval and ending in catastrophe. The Bible shows us the recovery from that state by the six days’ work ending in the appearance of Adam on the scene.
the earth existed for million of years before the Adamic Era
Fragments, however, of the pre-Adamic world have been brought to light by geological research organic remains, coal fields, and oil, belong to the ages before the formation of man, rather than to the time of the creation, or the flood.
If it be suggested that the fossil remains of the past include human remains, as well as remains of other races, the answer has to be made that there is a lack of scientific evidence that these remains are identical with the human race.
The animal and vegetable remains are those of species now largely extinct, belonging to pre-Adamic ages; and analogy would require that what are considered human remains, if they are human remains (which is by no means certain from the evidence) are the remains of an anterior race, existing at a remote time, when as yet the earth had not been overtaken by the convulsion which brought it to the state (developed in darkness and submerged in the deep) depicted to us in Genesis 1: 2.
that the earth existed prior to the literal six days of Adamic creation. That there was life on earth prior to a catastrophe which left the earth covered with water according to Yahweh's will.
In his discussion of the theory held by brother Roberts, brother Jardine and brother Simons that explained the geological and fossil record in terms of previous creations separated from the Adamic creation by a gap during which all life on earth was destroyed, brother Walker noted that there was actually sufficient scientific evidence to contradict this view. First he observed that the available evidence could not be reconciled with a 6,000 year old creation.
‘As with fishes, so with birds, many remains are found in the rocks, of a kind not now found upon earth. Our museums contain footprints of gigantic birds impressed in sand now turned to rock, and remains actually embedded in rock. If we understand Moses as teaching that the earth and all that therein is came into existence some 6,000 years ago, we shall scarcely be able to account for these evidently very ancient remains of creatures that do not now exist.’[4]
Brother Walker then demonstrated how the ‘gap between creations’ theory also lacked support from the available evidence. He noted that if such a gap had existed the fossil record would show this, when in fact the fossil record showed a continuity of earlier extinct life forms with later forms.
‘If we suppose a sudden and absolute break some 6,000 years ago, or before, resulting in the destruction of all life, and that the creation account of Genesis describes a new creation following, we ought to find some evidence of the break, and we cannot well account for the apparently close relationship that obtains between extinct and existing forms.
There are forms becoming extinct in our own day from slow and natural causes. May it not have been so in pre-Adamic times? The professors tell us for instance that some of these ancient birds, whose strides we can see for ourselves from their footprints were from four to six feet long, were like gigantic ostriches.’[5]
Supposing that it were ever established that they were the actual progenitors of our smaller forms (“There were giants in the earth in those days” might apply to birds and beasts), would the credibility of the Mosaic narrative suffer? Not at all, in our estimation. We should indeed have to revise somewhat our interpretation of the brief cosmogony of Gen. 1.; but should not waver as concerning its divinity, nor await with less faith and patience the reappearance of Moses in the land of the living.’[6]
Most of what is known of the Sabians comes from ibn Wahshiyya's The Nabatean Agriculture, translated in 904 CE from Syriac sources. The text discusses beliefs attributed to the Sabians, in particular that they were people who lived in Pre-Adamite times,