These three questions were asked separately by the same questioner. Because they are related, I answered them all together.
In Revelation 12 it kinda talks about Satan and his angels being cast to earth. Then in 13 it talks about him rising from the sea and the land so my question is since that has not happened yet does that mean Satan is not here right now? Or is it just his angels that are here?
Could there already be people receiving the mark of the beast since they are already slaves to sin and they reject Christ as their lord and savior?
When the rapture (the book of life) happens will people like myself who have faith and Christ and all he does and obey his commandments be here when Revelation 13 happens?
The problem with your question is your assumption that “this has not happened yet.” Since John was told that the things in the prophecy were “soon to occur,” (Revelation 1:1), they probably happened in the First or Second Century. Satan was cast down, his power broken, by the death of Jesus on the cross. If there is one thing that is clear in the New Testament, it is that Satan is present on Earth, working to take man captive. “And the God of peace shall bruise Satan under your feet shortly.” (Romans 16:20) “Satan hindered us.” (1 Thessalonians 2:18) “Be sober. Be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour.” (1 Peter 5:8) The fact that Satan is here, now, working in this world should indicate that Revelation 12 and 13 have already happened.
If we look closely at the book of the Revelation, we find that the beast of Revelation 13 is the same as “Babylon the great” of Revelation 17. One reason we can conclude this is that the following chapters both start with the identical statement, “Babylon the great is fallen, is fallen.” (Revelation 14:8; 18:2) In Revelation 17, John is clearly told that the beast, Babylon, is the city of Rome. Since the mark of the beast was to be given, then, by the Roman government, in the sense of the prophecy nobody can now receive the mark of the beast, because the Roman Empire fell hundreds of years ago. In the sense that there are still many followers of Satan, and for the reasons you stated in your question, then many are symbolically receiving the mark even today.
If by “the rapture” you mean that some people will be taken to heaven and others left for a while, and then the final judgement will happen, then this is not a concept taught in the Bible. The word “rapture” does not even appear in any common translation of the Bible. This is the first time that I have heard the “rapture” associated with the book of life. If the book of life is opened at the final judgement (if that is what Revelation 20 is talking about), then that would put the “rapture” at the same time as the final judgement, not some time before it. This would agree with 1 Thessalonians 4:17, “Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.” If there is a “rapture,” it is then end of the world rather than the concept being popularly taught for the past century and a half.
Will you be here when Revelation 13 happens? Since it happened, or began happening, 1900 years ago, I doubt you were there when it happened. If, in a sense, it continues happening, in the church, then you are here as it is happening, and may be a part of the triumph of Christ. That triumph has been happening for twenty centuries, and may continue for an unspecified period of time yet.
Then what is Jesus talking about in Luke chpt 21:36, ”pray that you be counted worthy to escape?” Isn’t that talking about some that can escape when people are being killed if they believe in God? (In Rev 21 when they talk about the thrones and the people we were beheaded, so am I going to be getting beheaded any time soon, since there is no rapture?) Or what about when it talks about 1 person will be in a field 1 taken and 1 left behind? Is that talking about the end? I’m confused. Another question I have, it says in Matt 24:14 about the gospel and how it will be preached. So once everyone on the globe knows about the gospel then will we see destruction? Or is this already going on right now also?
You appear to have been led astray, as many are today, by the teachings of someone who is not reading the whole context of a scripture. If you go back to verses 6-7 of Luke 21 you will see that the question the disciples of Jesus asked was about the destruction of the Temple, not the end of the world. So what he says in verse 36 about escaping these things is referring to the siege of Jerusalem that ended with the destruction of the Temple in 70 AD.
The same thing applies to the passages about one being taken and the other left. During the destruction that was to come on Jerusalem, some would die and others would be spared. Those who fled the city when they saw the signs Jesus listed would be spared.
Matthew 24:14 is also about the destruction of Jerusalem. It does say that the “gospel of the kingdom shall be preached in all the world” before the end of the things he has been talking about (the siege of Jerusalem) would come. That prophecy was fulfilled, according to Paul, before about 60 AD (ten years before the destruction of the Temple). “The gospel, which ye have heard and which was preached to every creature which is under heaven.” (Colossians 1:23) So the destruction that Jesus prophesied is not going on now, but was completed in 70 AD.
You also refer to being beheaded. In Revelation 20:4 it talks about those that had been beheaded (in the past). That doesn’t mean you won’t be beheaded for Christ, as is happening to some even today. It just means you don’t need to worry about being one of those in that passage.