Revelation 12:9 informs us that the dragon, also known as the Devil and Satan, "deceives the whole world." If God had not freed us from slavery and given us eyes to see things spiritually, such would still be our state. Jesus gives a similar description of our adversary:

You are of your father the devil, and the desires of your father you want to do. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it. (John 8:44)

Here, Jesus calls Satan the "father of lies." All of this world's deceptions originate in him, and wherever his spirit is present, destructive fruit, including deception, will be in evidence.

Satan has deceived the whole world, but it is important to note that he is not limited to a single deception. He does not have just one game or a singular tactic. The whole world is not deceived by Christmas and Easter and a triune godhead. One and a half billion Muslims have not fallen for these lies, nor have the legion atheists or followers of the various Eastern religions.

On the other hand, billions have not fallen for the deceptions of Buddha or Muhammad. So, while universal deception exists, it comes in more forms, shapes, and flavors than we can categorize. Satan does not have to get the whole world to believe the same thing to have everyone under his sway. Thus, just because a person recognizes the deceptions in the various pagan holidays does not mean that he is not deceived or cannot be deceived—it simply means that those particular deceptions do not have any hold on him at that point. Recognizing one lie does not mean that we are immune to all others.

Paul observes in II Corinthians 2:11 that "we are not ignorant of [Satan's] devices." This does not mean that, once we receive God's Spirit, we get a copy of Satan's playbook, and suddenly we know everything he is doing. Rather, Paul means that because we have been freed from spiritual slavery, we have eyes to see spiritually, and we can begin to recognize what is of God and what is not. We begin to understand some of the ways that Satan works, and we have the means to discern good fruit from bad. Though the danger of deception is lessened, it remains.