John 17:21
21 that they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me. NKJV
Do you take this phrase from John's Gospel to show that true believers are also God?
As to Isaiah 9:6, since one of the titles is "Everlasting Father" it is a great proof text for the Jesus only cult who believe that Jesus is God's NT name. Isaiah 9:6 also says the child will be called "Wonderful, Counselor" so do you believe that the Son is also the Holy Spirit?
Since you want to use Jesus' words to try to show He is God then what did Jesus mean when He prayed:
John 17:3
3 "And this is eternal life, that they may know Thee, the only true God, and Jesus Christ whom Thou hast sent. NAS
After you rationalize the Lord's own words then rationalize these:
Romans 16:27
27 to the only wise God, through Jesus Christ, be the glory forever. Amen. NAS
1 Corinthians 8:6
6 yet for us there is but one God, the Father, from whom are all things, and we exist for Him; and one Lord, Jesus Christ, by whom are all things, and we exist through Him. NAS
Let's see how Trinitarian commentators view Luke 10:18 since you want to take that one verse out of context:
Luke 10:18
And he said unto them, I beheld Satan as lightning fall from heaven.
[I beheld Satan ...] "Satan" here denotes evidently the prince of the devils who had been cast out by the seventy disciples, for the discourse was respecting their power over evil spirits. "Lightning" is an image of "rapidity" or "quickness." I saw Satan fall "quickly" or rapidly-as quick as lightning. The phrase "from heaven" is to be referred to the lightning, and does not mean that he saw "Satan" fall "from heaven," but that he fell as quick as lightning from heaven or from the clouds. The whole expression then may mean, "I saw at your command devils immediately depart, as quick as the flash of lightning. I gave you this power-I saw it put forth-and I give also now, in addition to this, the power to tread on serpents," etc.
(from Barnes' Notes, Electronic Database. Copyright (c) 1997 by Biblesoft)
Luke 10:17-20
And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name.
And the seventy returned. Their mission seems to have been successful. The Twelve failed to cure the demoniac boy (Luke 9:40); but the Seventy reported that even the demons fled at the mention of Jesus' name. 18. I beheld Satan as lightning fall. In the act of falling would be a fair translation. Jesus implied that the power of Satan was broken, and that the success of these disciples was an evidence of the victory. 19. Power is authority, the right to command. 20. Rejoice, because your names are written in heaven. The greatest cause for rejoicing is not the momentary victory over supernatural forces, but the eternal triumph of being enrolled among the citizens of heaven. Written may mean inscribed on a public register (cf. Hebrews 12:23; Revelation 3:5; 22:19).
(from The Wycliffe Bible Commentary, Electronic Database. Copyright (c) 1962 by Moody Press)
When did Satan fall from heaven like lightening? In Job we read that Satan has access to the throne of God to accuse the faithful. In Zechariah 3:1-2 Satan is accusing Joshua before God's throne. Satan's final defeat does not come until the end as recorded in Revelation 19.
"Before Abraham was I am" is another great proof text for the Jesus only cult. However, when you study how 1st century Jews and gentiles understood the concept of "logos" you will then understand that Jesus meant before Abraham was He was God's plan for the salvation of mankind. Jesus never claimed to be God.