"I am astonished that you are so quickly deserting him who called you into the grace of Christ and turning to a different gospel, not that there is a different gospel, but there are some who trouble you and want to pervert the gospel of Christ." (Galatians 1:6)
Calvinism, or "Reformed doctrine," is a false gospel because it preaches a different gospel than the true gospel delivered to the original Christians. Calvinism preaches a different Jesus. Of course, Calvinists are often found exclaiming they are the ones who believe the true gospel and everyone else believes a false gospel. Such self reaffirmations do not, however, make it so.
Now this does not mean that every single doctrine of Calvinism is untrue. For example, they believe the Bible is inspired and Jesus died on the cross for their sins and several other things which are true. The problem is not with these things but with distinctive errors which form the basis of their belief system. The core of Calvinism are the false doctrines of TULIP and all the teachings in Reformed Theology are designed to conform to and satisfy these five false doctrines, thereby significantly distorting the true gospel of our Lord Jesus Christ and nullifying the word of God for the sake of their tradition.
All five points of Calvinism are false doctrines. A man is not so totally depraved (T) that he is unable to respond to the gospel without being born again. Rather, upon hearing the gospel preached in the power of the Holy Spirit, he is able to respond to the gospel in faith so that he can be born again by the power of God. God did not predetermine which people would be saved for eternal life (U) and create others who have no possibility of being saved. The Bible teaches us that God knit us in our mother's womb. He did not create people for the express purpose of sending them to hell. Only Christ his Son was chosen before the foundation of the world. His Chosen One is Christ, his only begotten Son, and those who are united to Christ in faith become sons of God and chosen ones of God by virtue of their union with the Chosen Son of God. Christ did not die on the cross only for the sins of some people (L) but for the sins of all the people of the whole world. He is the sacrifice for all people and any number of sins of any number of men. God does not "drag" people irresistably to his Son (I) but invites people to have a relationship with him through his Son. And the Bible does not teach there is no real prospect of total apostasy from grace (P); rather those who do not stand firm in the faith may indeed fall short of salvation on the last day. All this we will decisively prove from the Holy Scriptures without fudging, straining Scriptures, or resorting to wild mental gymnastics and logical fallacies.
So how can YOU know for sure that it is Calvinism which preaches a false gospel? How can YOU know for sure the Calvinists do not proclaim the true gospel but proclaim a false gospel? The answer to that question is this website. The articles on this site expose the multitude of heinous falsehoods promoted in Calvinism. Here you will find out why each and every point of five point Calvinism (TULIP) is a false doctrine as well as false teachings which were contrived to conform to these false doctrines. This site illustrates the numerous errors of their belief system in a very clear and concise way that demonstrates for you just why Calvinism is most certainly and undoubtedly a false gospel.