WATCHERS & SONS OF GOD

According to the Books of Enoch the watchers fathered the giants. Enoch used to be part of the Bible but was removed in the 5th century. Two hundred watchers apparently came down on Mount Hermon and they led the people astray. This seems to be a seperate event from satan and a third of the angels that fell. Let’s see what the Bible says: 

 WATCHERS

It seems like watchers were angelic beings that came from Heaven and were placed on earth to protect the people. It’s possible that the watchers and the sons of God were the same angelic beings.
Melchizedek (Genesis; 14:18, Hebrews 7) was possibly a watcher and/or a son of God sent by God to curb sin, before the law.

Hebrews 7:1-3 MEV
For this Melchizedek, king of Salem, priest of the Most High God, met Abraham returning from the slaughter of the kings and blessed him. [2] To him Abraham also gave a tenth part of everything. In the first place, his name is translated "king of righteousness," and then also he is king of Salem, which means "king of peace." [3] Without father, without mother, without descent, having neither beginning of days nor end of life, but made like the Son of God, he continually remains a priest.

Strong’s H5341: to guard, protect, maintain, keep, preserve, to be kept secret, be hidden, watchman, observe, subtle
Jeremiah 4:16 NKJV
"Make mention to the nations, Yes, proclaim against Jerusalem, That watchers come from a far country And raise their voice against the cities of Judah.

Strong’s H5894: watcher(s), messenger, one who is a sentinel to guard and protect.
Daniel 4:13,17,23 NKJV
"I saw in the visions of my head while on my bed, and there was a watcher, a holy one, coming down from heaven. [17] 'This decision is by the decree of the watchers, And the sentence by the word of the holy ones, In order that the living may know That the Most High rules in the kingdom of men, Gives it to whomever He will, And sets over it the lowest of men.' [23] "And inasmuch as the king saw a watcher, a holy one, coming down from heaven and saying, 'Chop down the tree and destroy it, but leave its stump and roots in the earth, bound with a band of iron and bronze in the tender grass of the field; let it be wet with the dew of heaven, and let him graze with the beasts of the field, till seven times pass over him';

Jude and Peter spoke about angels that left their posts and they are waiting in chains for the judgement day. 

Jude 1:6 NKJV
And the angels who did not keep their proper domain, but left their own abode, He has reserved in everlasting chains under darkness for the judgment of the great day;

2 Peter 2:4-10 MEV
For if God did not spare the angels that sinned, but cast them down to hell and delivered them into chains of darkness to be kept for judgment; [5] and if He did not spare the ancient world, but saved Noah, a preacher of righteousness, with seven others, when He brought a flood upon the world of the ungodly; [6] and if He condemned the cities of Sodom and Gomorrah to destruction by reducing them to ashes, making them an example to those afterward who would live ungodly lives; [7] and if He delivered righteous Lot, who was distressed by the filthy conduct of the wicked [8] (for that righteous man lived among them, and what he saw and heard of their lawless deeds tormented his righteous soul day after day); [9] then the Lord knows how to rescue the godly from trial, and to keep the unrighteous under punishment for the Day of Judgment, [10] especially those who walk after the flesh in pursuit of unclean desires, and despise authority. They are presumptuous and arrogant, and are not afraid to slander the angelic beings.

1 Peter 3:18-22 MEV
For Christ also has once suffered for sins, the just for the unjust, so that He might bring us to God, being put to death in the flesh, but made alive by the Spirit, [19] by whom He also went and preached to the spirits in prison, [20] who in times past were disobedient, when God waited patiently in the days of Noah while the ark was being prepared, in which a few, that is, eight souls, were saved through water. [21] Figuratively this is like baptism, which also saves us now. It is not washing off the dirt from the body, but a response to God from a good conscience through the resurrection of Jesus Christ, [22] who has gone into heaven and is at the right hand of God, with angels and authorities and powers being made subject to Him.

SONS OF GOD

Unlike ordinary angels these sons of God could procreate. 

Genesis 6:1-8 MEV
When men began to multiply on the face of the earth and daughters were born to them, [2] the sons of God saw that the daughters of men were fair and took as wives any they chose. [3] The LORD said, "My Spirit will not always strive with man, for he is flesh; yet his days will be a hundred and twenty years." [4] The Nephilim were on the earth in those days, and also after that, when the sons of God came in to the daughters of men, and they bore children to them. These were the mighty men who were of old, men of renown. [5] The LORD saw that the wickedness of man was great on the earth, and that every intent of the thoughts of his heart was continually only evil. [6] The LORD was sorry that He had made man on the earth, and it grieved Him in His heart. [7] So the LORD said, "I will destroy man, whom I have created, from the face of the earth-both man and beast, and the creeping things, and the birds of the sky, for I am sorry that I have made them." [8] But Noah found grace in the eyes of the LORD.

Mark 12:24-25 MEV
Jesus answered them, "Do you not err, because you know neither the Scriptures nor the power of God? [25] When they rise from the dead, they neither marry nor are given in marriage, but are like angels in heaven.

Son: Strong’s H1121 - Hebrew Ben
Sons of God: Hebrew beney Elohim
Angels: Strong’s H4397 : mal’ak(malakim) - messenger, a human representative, a supernatural representative of God.
Strong’s G32: angelos - messenger

At times the sons of God would get together to meet with God. Satan also attended these meetings.

Job 1:6-8 MEV
Now there was a day when the sons of God came to present themselves before the LORD, and the Adversary also came among them. [7] And the LORD said to the Adversary, "From where have you come?" Then the Adversary answered the LORD, saying, "From roaming on the earth, and from walking up and down on it." [8] And the LORD said to the Adversary, "Have you considered My servant Job, that there is none like him on the earth, a blameless and an upright man, who fears God, and avoids evil?"

Job 2:1-2 MEV
Again there was a day when the sons of God came to present themselves before the LORD, and the Adversary came also among them to present himself before the LORD. [2] The LORD said to the Adversary, "From where do you come?" And the Adversary answered the LORD, saying, "From roaming on the earth, and from walking up and down on it."

Job 38:1-7 MEV
Then the LORD answered Job out of the whirlwind and said: [2] "Who is this who darkens counsel by words without knowledge? [3] Prepare yourself like a man; for I will question you, and you shall answer Me. [4] "Where were you when I laid the foundations of the earth? Declare, if you have understanding. [5] Who has determined its measurements, if you know? Or who has stretched the line upon it? [6] To what are its foundations fastened? Or who laid its cornerstone [7] when the morning stars sang together, and all the sons of God shouted for joy?

Isaiah 14:12 MEV
How are you fallen from heaven, O Lucifer, son of the morning! How you are cut down to the ground, you who weaken the nations!

It seems like satan was possibly a son of God before he fell. Jesus is also called the morning star. Jesus and satan/Lucifer/Helel possibly sang together when the Father created the earth and all the sons of God shouted for joy.

Revelation 22:16 MEV
"I, Jesus, have sent My angel to you with this testimony for the churches. I am the Root and the Offspring of David, the Bright and Morning Star."

God judged the gods or sons of God:

Psalm 82:1-8 MEV
God stands among the divine council; He renders judgment among the gods. [2] "How long will you all judge unjustly and accept partiality of the wicked? Selah [3] Defend the poor and fatherless; vindicate the afflicted and needy. [4] Grant escape to the abused and the destitute, pluck them out of the hand of the false. [5] "They have neither knowledge nor understanding; they walk in darkness: all the foundations of the earth are shaken." [6] I have said, "You are gods, sons of the Most High, all of you, [7] but you all shall die like men, and fall like a man, O princes." [8] Arise, O God, judge the earth, for You shall inherit all nations.

Psalm 89:6 MEV
For who in the skies can be compared to the LORD? Who among the heavenly sons is like the LORD?

These sons of God disappear in the New Testament since Jesus was the only son of God. 

John 3:16 MEV
"For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish, but have eternal life.

Jesus died and was resurrected and we could become sons of God.

Romans 8:14,19 MEV
For as many as are led by the Spirit of God, these are the sons of God. [19] The eager expectation of the creation waits for the appearance of the sons of God.

2 Corinthians 6:18 MEV
"I will be a Father to you, and you shall be My sons and daughters, says the Lord Almighty."

Galatians 4:6 MEV
And because you are sons, God has sent forth into our hearts the Spirit of His Son, crying, "Abba, Father!"

Philippians 2:15 MEV
that you may be blameless and harmless, sons of God, without fault, in the midst of a crooked and perverse generation, in which you shine as lights in the world.

1 John 3:1-2 KJV
Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not. [2] Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.