There has always been ET's... They are the eternal fallen angels Nephilim) as described in the book of Genesis:

Gen 6
4 The Nephilim were on the earth in those days-- and also afterward-- when the sons of God went to the daughters of men and had children by them. They were the heroes of old, men of renown. (NIV)

And, as Solomon wrote:
Eccl 1
9 What has been will be again, what has been done will be done again; there is nothing new under the sun.
10 Is there anything of which one can say, "Look! This is something new"? It was here already, long ago; it was here before our time. (NIV)

The Evil one owns this earth. He will part with it, though, he will make a deal.

Luke 4:5-7
5 The devil led him (Jesus) up to a high place and showed him in an instant all the kingdoms of the world.

6 And he said to him, "I will give you all their authority and splendor, for it has been given to me, and I can give it to anyone I want to.
7 So if you worship me, it will all be yours." (NIV)

So Satan tried his deal with Jesus, and failed. Now, he is offering us and all flesh the same deal. Land, power, control and money. And, he has plenty of folks who took him up on it.

We will talk about why they bother in a moment, but first let us recognize that they have PLENTY of human help.

You know...they are the ones among us who detail great fantasies
about "Galactic Federations", so-called "channeled" messages from long dead folks, ET missives, letters from earth gods, goddesses and the like.

You see, by his very nature as God's adversary, Satan's continued very existence depends on him being victorious over God. He tried and failed miserably with Jesus, because Jesus overcame his hold on death. Hence, Satan can only rule the flesh.

And THAT, folks is the ONLY reason the "ET's" want to "save" us.
Guard your spirit with care, folks for that is the ONLY 'you' that matters.

Heb 2:
13 And again, "I will put my trust in him." And again he says, "Here am I, and the children God has given me."
14 Since the children have flesh and blood, he too shared in their humanity so that by his death he might destroy him who holds the power of death-- that is, the devil--
15 and free those who all their lives were held in slavery by their fear of death.
16 For surely it is not angels he helps, but Abraham's descendants.

If you are a Christian, you are His descendants and Satan's prime target.

And, you know what? Much of Satan's crap is exactly on target and growing daily. The chief deceiver and his nephilim minions will make it happen, in time.
See here:

Rev 13:
8 All inhabitants of the earth will worship the beast-- all whose names have not been written in the book of life belonging to the Lamb that was slain from the creation of the world.
9 He who has an ear, let him hear.
12 He exercised all the authority of the first beast on his behalf, and made the earth and its inhabitants worship the first beast, whose fatal wound had been healed.
13 And he performed great and miraculous signs, even causing fire to come down from heaven to earth in full view of men.

Sounds like pretty powerful ET's huh? Yeah, they are.

Now, just WHY would they want to 'save' everyone? Here's a clue.. They really don't WANT to save EVERYONE...Satan just wants to save his own followers. Which he will for a few (3 1/2) days.. Satan and his minions want to destroy Christians and their beliefs. But, Satan's tricks only work on the flesh.

And, you must admit Satan's flesh followers are doing a fine job of destroying Christian beliefs in this world today.

Well, long story short...they WILL defeat every one of us in this flesh life, but Satan and his minions will lose it all in the end, as they are totally destroyed, forever...

The last to die a flesh death will be the two witnesses, who emerge "out of nowhere" with all the power they need and piss off lots of flesh folks...and the minions will be powerless for a while.

Rev 11:3-15
3 And I will give power to my two witnesses, and they will prophesy for 1,260 days, clothed in sackcloth."
4 These are the two olive trees and the two lampstands that stand before the Lord of the earth.
5 If anyone tries to harm them, fire comes from their mouths and devours their enemies. This is how anyone who wants to harm them must die.
6 These men have power to shut up the sky so that it will not rain during the time they are prophesying; and they have power to turn the waters into blood and to strike the earth with every kind of plague as often as they want.
7 Now when they have finished their testimony, the beast that comes up from the Abyss will attack them, and overpower and kill them.
8 Their bodies will lie in the street of the great city, which is figuratively called Sodom and Egypt, where also their Lord was crucified.
9 For three and a half days men from every people, tribe, language and nation will gaze on their bodies and refuse them burial.
10 The inhabitants of the earth will gloat over them and will celebrate by sending each other gifts, because these two prophets had tormented those who live on the earth.
11 But after the three and a half days a breath of life from God entered them, and they stood on their feet, and terror struck those who saw them.
12 Then they heard a loud voice from heaven saying to them, "Come up here." And they went up to heaven in a cloud, while their enemies looked on.
13 At that very hour there was a severe earthquake and a tenth of the city collapsed. Seven thousand people were killed in the earthquake, and the survivors were terrified and gave glory to the God of heaven.
14 The second woe has passed; the third woe is coming soon.
15 The seventh angel sounded his trumpet, and there were loud voices in heaven, which said: "The kingdom of the world has become the kingdom of our Lord and of his Christ, and he will reign for ever and ever." (NIV)

Rev 20
1 And I saw an angel coming down out of heaven, having the key to the Abyss and holding in his hand a great chain.
2 He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years.
3 He threw him into the Abyss, and locked and sealed it over him, to keep him from deceiving the nations anymore until the thousand years were ended. After that, he must be set free for a short time. (NIV)

And from there on it gets really interesting...stay tuned, and remember what Solomon said...

Eccl 1
9 What has been will be again, what has been done will be done again; there is nothing new under the sun.
10 Is there anything of which one can say, "Look! This is something new"? It was here already, long ago; it was here before our time. (NIV)