In the series "Ancient Aliens", on the History Channel, the host Giorgio A. Tsoukalos, proposes the idea that ancient alien astronauts seeded life on earth, and interacted with humans to build ancient ruins, temples and pyramids. He believes that extraterrestrial beings came to earth in ancient times and helped shape history. He asks the question that if ancient aliens didn't exist, then how did man build everything? Good question, perhaps I can offer an another explanation...
In the book of Genesis, we see this:
Genesis 6:1-4 (KJV)
1 And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them,
2 That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
3 And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.
4 There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
The sons of God (angels), saw the daughters of men that they were fair. The women bore children unto them, mighty men that were Giants. They were hybrid beings - half man, and half angel. They were incredibly large, strong, and powerful. According to the translation of the Book of Enoch by R. H. Charles, the 1st generation of these "mighty men" were 3,000 ells tall. It appears that this may be a typo, and a translation of the Book of Enoch by Reverend Richard Laurence states that they were 350 ells tall. This would mean that the first generation of giants were around 450 feet tall. That's about as tall as the Great Pyramid of Giza!
Is it not possible that the giants described in Genesis could have been responsible for building these massive structures? The Giza Pyramid stands at an impressive 455 feet, and was also known as the Pillar of Enoch. The Giants 1st appeared in Enoch's time as his book gives an in depth description of them, what they did, and how they petitioned Enoch to go before the Lord.
Back to the alien question... Could there be extraterrestrial life on other planets? It is simply not Biblical. If it were true, why would God not mention it in his Word?
The problem here is SIN. Man is sinful. It is in our nature and goes back to Adam's disobedience at the Garden of Eden. The old Jewish nation received instruction by God on performing animal sacrifices for cleaning their sins. This was a "quick fix", as they would sin again and have to perform more sacrifices. The "permanent solution" came when God sent his only begotten Son who was born of a virgin; tempted as we are; yet without sin. Jesus paid our price for our transgressions and sacrificed himself on the cross so that we could become new creatures in Christ (born again) and be forgiven of our sins. All we have to do is repent, believe in who He is and receive his Holy Spirit who leads us into all truth. If we surrender ourselves to Him, He in return, sanctifies and saves our souls. He proved who he is by dying, resurrecting, and ascending to Heaven. He is now sitting at the right hand of God the Father.
So we see that man has the problem and condition of sin, which separates us from God. So also did the angels - 200 of them rebelled against God (before Noah's flood), seduced women, provided information we weren't supposed to know, all while committing unholy unions with women which produced half-breed giants that consumed the world. Lucifer (Satan) also sinned by trying to usurp the throne of God.
Isaiah 14:12-14 (KJV)
12 How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!
13 For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:
14 I will ascend above the heights of the clouds; I will be like the most High.
"I will ascend into heaven... exalt my throne above the stars of God... sit on the mount of the congregation...be like the Most High..." Pride and lust are the themes here. It appears that the three things the enemy uses to cause us to sin are the lust of the eyes, the lust of the flesh, and the pride of life. This is evidenced in 1 John 2:16. The Devil used these three things to cause sin to enter into the Garden and into man. In Genesis, we see the three;
Genesis 3:6 (KJV)
6 And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat.
"Was good for food" = Lust of the flesh
"It was pleasant to the eyes" = Lust of the eyes
"Desired to make one wise" = Pride of life
These are the same three things that were found when Jesus was tempted by Satan in the fourth chapter of Matthew.
"Stones to be made bread" = Lust of the flesh
"All the kingdoms" = Lust of the eyes
"Cast yourself down" = Pride of life
If sin is not limited to just man, then it is reasonable to assume that if there was alien life in other worlds, they too would be subject to sin as well. If the solution to sin is in the sacrifice of God's son, then Jesus would have to sacrifice himself multiple times on various planets as well.
Romans 6:10 (KJV)
10 For in that he died, he died unto sin once: but in that he liveth, he liveth unto God.
"For in that he died, he died unto sin ONCE..." (Not multiple times). Therefore, how could there be life on other planets?
Your thoughts and opinions are welcome.