Very serious. If the narrative is that one is predestined to either Heaven or hell, then why should one avoid sin? From either position?
If you believe that you are predestined to heaven, then since you are going to be ultimately rewarded with salvation, why not go through life having as much self-serving fun as you can?
Else, if you are predestined to hell, why not just turn vindictive and take it out on the rest of humanity? Well?
In either case, Reformed beliefs can lead to an immediate self-serving attitude.
Excellent questions! And of course these tie into the original topic - Tornadoes.
Ultimately, the question boils down to the sovereignty of God.
I could do as you say and lead a "self-serving fun" life. The problem however, is you start from a false premise - that there is a "fun" life apart from God. Obviously, there is pleasure to be had in sex, drugs, drink, money, power - otherwise we wouldn't be drawn to them. But the truth is that the "fun" life-style is an empty construct - it is a lie from the pit. It is a meaningless pursuit that will lead to ruin, despair & isolation.
As I mentioned earlier, CS. Lewis explains it well:
"If we consider the unblushing promises of reward and the staggering nature of the rewards promised in the Gospels, it would seem that Our Lord finds our desires not too strong, but too weak. We are half-hearted creatures, fooling about with drink and sex and ambition when infinite joy is offered to us, like an ignorant child who wants to go on making mud pies in a slum because he cannot imagine what is meant by the offer of a holiday at the sea. We are far too easily pleased."
So you can see that the question of a "self-serving fun life" is moot.
Or is it? Do you understand how Piper arrived at the phrase "Christian Hedonist"? It is provocative - he knows that - it was meant to be. The knee-jerk reaction to the phrase is to exclaim "hah - see! Piper thinks he can do what he wants 'cause he thinks he's predestined to heaven". And that would be the wrong response.
Piper understood two truths early on in life.
1. Because we recognize the great love with which God loved us in the giving of his Son, everything we do in this life should be done as an outpouring of our gratitude and love for God ("...whatever you do, do it for the glory of God").
2. He wanted to be happy.
You see, it was the above insight from C.S Lewis along with a few other historical individuals, that made him realize that the the above two truths were NOT mutually exclusive. In fact they are complementary.
Consider the parable of the man who found a treasure in a field (the kingdom of God). What was his response? He went and sold EVERYTHING he had so that he could buy the field. That man was a Christian Hedonist! He denied himself EVERYTHING ELSE. He recognized that his happiness was bound to the King and the Kingdom.
Back to the point of God's sovereignty. If we accept that God loves us as his children, and that a good father disciplines his children, so we must accept that God will discipline us - as HE sees fit. If we are HIS, he will not (ultimately) allow us to continue pursuing your "self-serving fun" life. Because he loves us - and for HIS NAMES SAKE, he will show HIMSELF to be preferable - to making mud pies in the slum...
Grace to you