Yes, Lucifer was in Heaven before he sinned, and sinned in Heaven, even as Adam was in the Garden of Eden on earth and there was no sin it it, and he sinned therein:When he was in Heaven and there's no sin in Heaven? Also, would God forgive him if he repented?
2Pe_2:4 For if God spared not the angels that sinned, but cast them down to hell [Tartarus, a place of darkness, out of Heaven into the blackness of 'space', where they eventually came to this newly created world], and delivered them into chains of darkness, to be reserved unto judgment;
Jud_1:6 And the angels which kept not their first estate [arch-offices], but left their own habitation [places God them to occupy, their purpose], he hath reserved in everlasting chains under darkness unto the judgment of the great day.
Isa 14:12 How art thou fallen from heaven, O Lucifer, son of [child of, by creation] the morning [Jesus Christ, the Morning Star]! how art thou cut down to the ground, which didst weaken the nations!
Isa 14:13 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:
Isa 14:14 I will ascend above the heights of the clouds; I will be like the most High.
Isa 14:15 Yet thou shalt be brought down to hell, to the sides of the pit.
Isa 14:16 They that see thee shall narrowly look upon thee, and consider thee, saying, Is this the man that made the earth to tremble, that did shake kingdoms;
Isa 14:17 That made the world as a wilderness, and destroyed the cities thereof; that opened not the house of his prisoners?
Isa 14:18 All the kings of the nations, even all of them, lie in glory, every one in his own house.
Isa 14:19 But thou art cast out of thy grave like an abominable branch, and as the raiment of those that are slain, thrust through with a sword, that go down to the stones of the pit; as a carcase trodden under feet.
Isa 14:20 Thou shalt not be joined with them in burial, because thou hast destroyed thy land, and slain thy people: the seed of evildoers shall never be renowned.
Eze 28:12 Son of man, take up a lamentation upon the king of Tyrus [the real Ruler of Tyrus, was not a person of mankind, but the fallen archangel Lucifer/satan/Leviathan (King over all the children of pride; Job 41:34)], and say unto him, Thus saith the Lord GOD; Thou sealest up the sum, full of wisdom, and perfect in beauty.
Eze 28:13 Thou hast been in Eden the garden of God [this Eden was not the one on Earth, but the one that existed before in Heaven, Genesis 2:8, for the one on earth was not 'created', it was "planted", that is transplanted from the one in Heaven, where God Himself dwells, Luke 23:43; 2 Corinthians 12:2,4; Revelation 2:7]; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
Eze 28:14 Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God [the original Mount Zion in Heaven itself]; thou hast walked up and down in the midst of the stones of fire.
Eze 28:15 Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
Eze 28:16 By the multitude of thy merchandise they have filled the midst of thee with violence, and thou hast sinned: therefore I will cast thee as profane out of the mountain of God: and I will destroy thee, O covering cherub, from the midst of the stones of fire.
Eze 28:17 Thine heart was lifted up because of thy beauty, thou hast corrupted thy wisdom by reason of thy brightness: I will cast thee to the ground, I will lay thee before kings, that they may behold thee.
Eze 28:18 Thou hast defiled thy sanctuaries by the multitude of thine iniquities, by the iniquity of thy traffick; therefore will I bring forth a fire from the midst of thee, it shall devour thee, and I will bring thee to ashes upon the earth in the sight of all them that behold thee.
Eze 28:19 All they that know thee among the people shall be astonished at thee: thou shalt be a terror, and never shalt thou be any more.
Lucifer argued with God in Heaven, and convinced others (nearly half; Revelation 12:4) of his arguments (see Ezekiel 28, "merchandise", "traffick", in other words trading in thoughts/ideas/speeches).
Rev 12:4 And his tail drew the third part of the stars of heaven, and did cast them to the earth: and the dragon stood before the woman which was ready to be delivered, for to devour her child as soon as it was born.
Rev 12:7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
Rev 12:8 And prevailed not; neither was their place found any more in heaven.
Rev 12:9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
Rev 12:10 And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
Rev 12:7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
Rev 12:8 And prevailed not; neither was their place found any more in heaven.
Rev 12:9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
Rev 12:10 And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
As God dealt with Cain:
Gen_4:7 If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him.
As God dealt with Judas in mercy, even to the very last:
Joh 13:4 He riseth from supper, and laid aside his garments; and took a towel, and girded himself.
Joh 13:5 After that he poureth water into a bason, and began to wash the disciples' feet, and to wipe them with the towel wherewith he was girded.
Joh 13:12 So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you?
Joh 13:5 After that he poureth water into a bason, and began to wash the disciples' feet, and to wipe them with the towel wherewith he was girded.
Joh 13:12 So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you?
As God has dealt with all, He also dealt with Lucifer in Heaven:
Heb 13:8 Jesus Christ the same yesterday, and to day, and for ever.