John Calvin is revered by many as a great reformer and formulator of doctrine. This must be examined by the light of scripture and history to see if it is true. Summed up, Calvinism has 3 main points:
1. Unconditional eternal security
2. Predestination of individuals
3. Faith alone without works
Each of these do not hold up to scriptural scrutiny. This subject cannot be thoroughly examined in a few paragraphs of a blog. I suggest you get my book "Faith and Works" which is available through this website and at amazon.com for a deeper look at these things. The bottom line is that Calvinism says we are not responsible for our actions. God determines who is saved and who is not, independent of what choices we make or what we do. It says that our actions play no part whatsoever in determining this. This is a dangerous doctrine which causes people to have a false concept of God and what He expects from us. We cannot build a correct relationship with God on an incorrect foundation. Martin Luther and Calvin sought to deal with guilt differently than Catholicism was teaching in their day, but they went to the other extreme. Catholicism was teaching that people could buy "indulgences" for sin. They said you don't have to do anything at all. That is not what the Bible teaches. The Bible says we cannot earn forgiveness or salvation. God gives it to us freely. The basis upon which God saves us is His grace, not our works. However, that does not mean we do not have to do anything, especially after we are saved.
The Bible says you will know a tree by its fruit, and that every tree which does not bear good fruit is cut down and thrown into the fire (Mt 3:10, Mt 7:17-19, Mt 12:33). 1John 4:1-3 says that every teaching has spiritual repercussions, and should be tested. Whole denominations of Christianity are dying spiritually and numerically because there is no real call for a changed life and no manifestation of the power of God to cause it.
The Jews in both the time of the Old Testament and the New Testament fell into a form of Jewish Calvinism. They rested on their identity as descendants of Abraham and did not seek for the righteousness that only God can bring into a life. They were religious, but they did not know God. John the baptizer, Jesus, and the apostles challenged their presumptions and they hated them for it. John Calvin was involved in the murder of prominent apostolic preacher Michael Servetus, who was burned at the stake for preaching the same thing the apostles did. Servetus dared to contradict Calvin by the scriptures. Religion has always hated true relationship with God.
How does Calvinism play out practically in every day life as well? Some people think they have an entitlement to the benefits of working without actually having to work themselves. Likewise, some people want all the benefits of the Christian life without actually living it. Others think they can just verbally declare whatever identity they choose, and God and everyone else is supposed to ignore biology and every other evidence to the contrary and accept who they say they are. This is insane. If I decide to declare that I am a quadriplegic of Asian descent, that does not change my lineage or the fact that all my limbs work. If I declare that I am actually an oak tree, that does not make it so. Christians should love those who are battling identity and orientation issues without approving unbiblical approaches. Yet some people think they can just call themselves Christians, and that makes it so. It is not they who call themselves Christians, but they whom God calls Christians. As it is said, being in a church building does not make you a Christian any more than being in a garage makes you a car. Who we say we are must match our behavior. No one is perfect, but our overall lifestyle should reflect the values we say we believe. Christianity is not a superficial religion of verbal acknowledgements and mental assents. It is a true relationship with God, others, and self based on the scriptures.