There is no such thing as demonic bloodlines in the Bible. There are only human bloodlines. Demons cannot procreate and sire any offspring. They never have and never will. To believe that the giants were 450 feet tall is believing in a complete lie.
The books in the Bible are all the books that we need and God had preserved them through the ages and forever. God is in complete control of everything including His Word, He is the one the put it together and inspired it (
2 Timothy 3:16; 2 Peter 1:20-21). There is nothing missing in His Word. If its not in the Bible, its not meant to be and its no coincidence its not I'm afraid.
The Bible contains everything a person needs to know and do in order to be saved. All truth necessary for salvation and spiritual life is taught either explicitly or implicitly in Scripture. The Bible reveals God’s will and points us to Jesus, who saves us from our sins (
John 5:39; 20:31). Also the Bible is clear enough that anyone can read it for himself or herself and discover the basic path to salvation. That doesn't mean that we don't need pastors, teachers, or Bible commentaries to help us understand the Bible. The Bible contains things that are difficult to understand (
2 Peter 3:14-16). It has depths of meaning beyond what any of us see. But it’s basic message of salvation is simple enough and clear enough for anyone to understand and follow. These people have have got to teach Bible doctrine and nothing else.
And when it comes to the book of Revelation,
chapter 1 verse 3 says,
"Blessed is he who reads and those who hear the words of this prophecy, and keep those things which are written in it; for the time is near." The book of Revelation was written to show God's people
"things which must shortly come to pass" (
Revelation 1:1). This is true for all generations of God's people—from the time it was written to the very end of time. God has always wanted His people to be informed, aware, and warned about future difficulties. Plus
Revelation 1:1 says,
"The Revelation of Jesus Christ, which God gave Him to show His servants—things which must shortly take place. And He sent and signified it by His angel to His servant John." The word
"Revelation" means
“an unveiling of.” The book of Revelation is the
“Revelation of Jesus.” He is its author; it is a message straight from Him. So none of it is sealed (as some claim it is) nor is there anything missing from it.
Overthinking is bad when it takes you away from the Word of God. The Bible is the only authority for what Christians should believe and practice.