I am not sure that it was the first lie. We don't know exactly how Lucifer convinced other angels to rebel against God. Was it by mean of lies? We don't know. And I have my reserves considering those words of Satan to Eve as lies. In fact, Adam and Eve lived long lives after eating the figue. Adan and Eve did not die right after eating but many centuries after. And the first consequence of eating from the figue tree was to have their eyes opened and knowing the difference between good and evil; exactly what Satan was saying.
Let's go with the first recorded lie, since we have no way of knowing what lies Satan told previously...
Joh 8:44 Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own:
for he is a liar, and the father of it.
Anyhoo, the first recorded lie...
Gen 3:4 And the serpent said unto the woman,
Ye shall not surely die:
God said they would die...
Gen 2:17 But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof
thou shalt surely die.
die:
H4191
מוּת
mûth
mooth
A primitive root; to die (literally or figuratively); causatively to kill: - X at all, X crying, (be) dead (body, man, one), (put to, worthy of) death, destroy (-er), (cause to, be like to, must) die, kill, necro [-mancer], X must needs, slay, X surely, X very suddenly, X in [no] wise.
Death, not life in another place, death. Satan (the whispering enchanter) then said...
Gen 3:4 And the serpent said unto the woman,
Ye shall not surely die:
Gen 3:5 For God doth know that in the day ye eat thereof, then your eyes shall be opened,
and ye shall be as gods, knowing good and evil.
You will be like God, you will have immortality (an immortal soul), you won't die. We do not have immortality, we have to put it on...
1Co 15:53 For this corruptible must put on incorruption, and this mortal must put on immortality.
1Co 15:54 So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.
1Ti 6:16 Who only hath immortality, dwelling in the light which no man can approach unto; whom no man hath seen, nor can see: to whom be honour and power everlasting. Amen.
We are promised life, but it is the gift of God...
Rom 6:23 For the wages of sin is death;
but the gift of God is eternal life through Jesus Christ our Lord.