Calvin firmly believed that everything we can know about God is strictly limited to what God has revealed about himself. Calvin further believed that God has revealed through Scripture only that which is necessary for human beings to enter into a covenant relationship with him. Beyond this revelation, God is a mystery to his creation and will remain so. Without question Calvin believed in the doctrine of the Trinity devoting an entire chapter in Book First to the topic. Calvin states in no uncertain terms that God the Father, God the Son, and God the Holy Spirit are three distinct, coequal of the God-head though he also bemoans the poverty of human language in the ability to adequately express the concept.
Though Calvin affirmed his belief in the Trinity among other doctrines, Calvin was well known for his stance on the sovereignty of God with respect to the elect. In his commentary on Romans 9, Calvin clearly articulates the view that God predestined those whom He would to have come to knowledge of Himself and that without God’s moving man would never come to that knowledge. Calvin, never shying away from controversy, goes on to reinforce God’s sovereignty by driving home the importance of the use of the term elect in Romans 9:11discussing the unborn. This selection by God is independent of anything a human being might do to attain salvation. In fact, there is nothing that a sinner can do to merit salvation apart from the grace of God. Calvin made no apologies for his belief that God not only created the universe but is also actively involved in the affairs of His creation that would one day culminate in the completion of His purpose; bringing glory to Himself.
While Calvin enthusiastically believes in election or predestination it should be noted that Calvin is not silent on those who are not elect. Even had Calvin neglected to mention the fate of those who are not elect, it is a logical step to assume that the reprobate will not enter heaven. Fortunately, Calvin wisely addressed the reprobate. In Book Third, Calvin further articulates his view that while God certainly does adopt some to the hope of eternal life, others he adjudges to eternal death. Lost on many a commentator is the fact that Calvin, while believing that there was a practical significance for studying the doctrine of predestination and it was not merely an academic exercise, also warned against delving too deeply into this.
 Erickson, Millard J. Christian Theology 2nd Edition. (Grand Rapids: Baker Academic, 1998), 926. Erickson summarizes this point well. For the entire statement on this warning see Calvin’s Institutes of the Christian Religion, Book Third, Chapter 21, Section 1. There Calvin again makes mention of the mystery of God and the comfort he has with such mystery. Calvin understood clearly that God has not revealed all there is to the creation but only that which is necessary for human beings to coming to a knowledge of Him.