What Jesus did on the cross was not casual and it should be honored for what it was and is: the act of God whereby it was made possible for us to be taken from darkness to Light
While no one will deny that many of our prominent founders were Calvinists, there were others who were not.
Why did you believe the gospel, but your friend did not? Are you wiser or smarter or more spiritual or better trained or more humble?
To call something a “Christian liberty” means it is NOT an essential to Christianity. Unlike the essential doctrines of the church, a liberty is something I am free to practice or not practice.
Is a person saved BECAUSE he repents and by faith believes in the finished work of Christ on the cross or is a person saved so that he can THEN by faith repent and believe in the finished work of Christ on the cross?