This is very contentious!! The first recorded sin in the Bible is certainly that of Gen 3 - but that begs the question: If Satan was responsible for tempting Eve and Adam, then Satan must have sinned and fallen into sin prior to this point.
We are not told how much time there was between Stan's initial downfall and the incident in Gen 3; but there must have been some time. See appendix below.
Thus, God and other heavenly beings would have been aware of Satan's "evil" intentions before the Gen 3 incident.
APPENDIX - Satan
If, as many believe, the Book of Job is the earliest book of the Bible ever written, then "Satan" appears in the first chapter. Here is a list of cases where "Satan" appears as a person with super-human capabilities and as adversary:
- Job 1:6, 7 - One day the sons of God came to present themselves before the LORD, and Satan also came with them. “Where have you come from?” said the LORD to Satan. “From roaming through the earth,” he replied, “and walking back and forth in it.” See also Job 1:8, 9, 12, 2:1, 3, 4, 6, 7.
- Zech 3:1 - Then the angel showed me Joshua the high priest standing before the angel of the LORD, with Satan standing at his right hand to accuse him.
- 1 Chron 21:1 - Then Satan rose up against Israel and incited David to take a census of Israel.
In the NT, "Satan", Σατανᾶς is a transliteration of the Hebrew, שָׂטָן and occurs 36 times in the NT from Matthew to Revelation. Significantly, as BDAG describes this word thus:
in our literature, only as a title or name: (the) Satan , in a very
special sense, the enemy of God and all those who belong to God,
simply, Satan, the enemy ... almost always with the article. [For more
details in the extensive entry, see BDAG.]
Note that not only does Σατανᾶς almost always appear with the article, but it also occurs in the vocative case, eg, Matt 4:10, 16:23, Mark 8:33, where Jesus directly addresses Satan.
In two places in Revelation Satan is given alternate titles:
- Rev 12:9 - The great dragon was hurled down--that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him.
- Rev 20:2 - He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years.
This confirms what is already revealed in other places that when διάβολος has the article, “The Devil”, it is referring to "Satan", eg,
- Compare Matt 4:1, 5, 8, 11 with V10
- Luke 4:2, 3, 5, 6, 13 tells the same story of Jesus' temptations.
In Matt 10:25, 12:24, 27, Mark 3:22, Luke 11:15, 18, 19, Satan is given the name Βεελζεβούλ, (Beelzeboul), "lord of flies", a false god of the Ekronites (2 Kings 1:2) - a Jewish name of extreme contempt.
In the rest of the New Testament Satan is either given the proper name “Satan” (Acts 5:3, 2 Cor 2:10, 11, 11:14, 2 Thess 2:9, 10, 1 Tim 5:14, 15, Rev 3:9), or “devil” (Matt 4:10, 11, 2 Tim 2:26, Eph 6:11, Rev 12:9, 1 John 3:8), “the serpent” (Rev 12:9, 15, 20:2), “the dragon” (Rev 12:9, 20:3), “Beelzebub” (Matt 12:24), “Belial” (2 Cor 6:15), “the temper” (Matt 4:3), “the enemy” (Matt 13:39), “the evil one” (Matt 5:37, 13:35, John 17:15, 2 Thess 3:3, 1 John 2:13, 14, 5:18), “the adversary” (1 Peter 5:8), “the thief” (John 10:10), “father of lies” (John 8:44), “the god of this world” (2 Cor 4:4), “prince of the power of the air” (Eph 2:2), “ruler of this world” (John 12:31), and “the deceiver” (Rev 12:9).
Thus, both the OT and the NT treat Satan as personal being just as much as any other person whether human or superhuman, including vocative address. The theology of Satan is far more highly developed in the NT than the OT.
Several passages in the NT describe Satan and his minions as falling from heaven to earth such as Luke 10:18, Rev 8"10, 9:1, 12:8, 9, 13. These all appear to allude to the poetic/symbolic references in Isa 114:12-15 and Eze 28:12-17.
Lastly, the naming of Satan as the "serpent" in Rev 12:9, 20:2 appears to allude to the very thinly veiled description of the serpent in Gen 3.