1 John 2:22
 Who is the liar but he who denies that Jesus is the Christ? This is the antichrist, he who denies the Father and the Son. (ESV)
In our current culture we seem to be afraid to be firmly committed to any truth. It is thought that if we define things in terms of truth and lies we have become extremist, and are maybe even dangerous people. As a result of blurring the lines between truth and falsehood it becomes more difficult for the Church to speak to these things. The fact is, the Bible is very clear about truth and falsehood. In this book of 1 John, the Apostle is countering the false teachers who were infiltrating the church.
It may make some folks in our current society to hear the Apostle John's words, but he is very direct about truth and lies. "Who is the liar but he who denies that Jesus is the Christ?" John does not stop there. He calls such a liar the antichrist. Can you imagine confronting people that you know as being the antichrist because they deny that Jesus is the Christ? Did you know that for many years the pope of the Roman Catholic church was perceived in just this way. Consider the great Protestant Reformer Martin Luther:
"The identification of the Pope as the antichrist was so ingrained in the Reformation era (for obvious reasons) that Luther stated it repeatedly. For example: “This teaching [of the supremacy of the pope] shows forcefully that the Pope is the very Antichrist, who has exalted himself above, and opposed himself against Christ, because he will not permit Christians to be saved without his power, which, nevertheless, is nothing, and is neither ordained nor commanded by God” (Smalcald Articles, II).
I want you to consider the fact that Christ is to be supreme in all things. He alone is the author and finisher of our faith. He is to be glorified above all others. He is God in the flesh. He has conquered death for all who place their faith in Him. I do not want to call anyone the antichrist, but be sure that in your heart you have not denied Jesus his absolute authority in your heart.
 He is the image of the invisible God, the firstborn of all creation.  For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him.  And he is before all things, and in him all things hold together.  And he is the head of the body, the church. He is the beginning, the firstborn from the dead, that in everything he might be preeminent.  For in him all the fullness of God was pleased to dwell,  and through him to reconcile to himself all things, whether on earth or in heaven, making peace by the blood of his cross. (ESV)