Just as Spurgeon made this claim we read it below here from PRCA website - Calvinist- Protestant Reformed Churches of America.
“Calvinism is the Gospel. Its outstanding doctrines are simply the truths that make up the Gospel. Departure from Calvinism, therefore, is apostasy from the Gospel of God's grace in Christ. Our defense of Calvinism, then, will proceed as follows. First, we will show that Calvinism is the Gospel. This is necessary because of its detractors, who criticize it as a perversion of the Gospel. Second, we will defend it as the Gospel. In doing this, we carry out the calling that every believer has from God. Paul wrote that he was "set for the defense of the Gospel" (
Philippians 1:17).
I Peter 3:15 calls every believer to give an answer, an "apology," or defense, to everyone who asks us a reason for the hope that is in us. As the name indicates, Calvinism is a certain teaching associated with John Calvin; it refers to Biblical doctrines that he propounded.”
“Calvinism, then, can rightly be viewed as certain basic doctrines, the so-called "five points of Calvinism."
http://www.prca.org/pamphlets/pamphlet_31.html
Conclusion : once again I’m right most Calvinists do not know what Calvinism teaches.
hope this helps !!!