Theologically, Calvinists use these terms to describe the order in which God determined events would happen in His relationship to people. The larger umbrella term to describe these is predestination.
What are the theological concepts of infralapsarianism, sublapsarianism, and supralapsarianism?
Getting to the ultimate understanding of these terms and their implications is beyond grasping with our (human) limited insight. Whether infralapsarianism, sublapsarianism, or supralapsarianism is the most biblical does not significantly impact our understanding of God, nor our relationships with other people. What does matter is that God created humans, humans sinned, and God provided a way back into relationship with Him (salvation) through Jesus Christ.
That said, what follows is a brief definition of each of these three ideas. The term lapsarian is related to the word lapse. The fall of humankind into sin is seen as a lapse. Infralapsarianism, sublapsarianism, and supralapsarianism each describe an order in which God decreed certain events in relation to this lapse.
With infralapsarianism ("after the lapse"), that order is described as God creating humans, God allowing humans to sin because of their self-determination, God deciding to save some sinners, and finally God deciding to send Jesus Christ as the Redeemer. The focus of infralapsarianism centers on God's decision to allow self-will and sin, followed by salvation. Most Calvinists adhere to this framework.
Sublapsarianism ("under the lapse") is similar. It explains the events as: God decided to create humans, God decided to allow sin, God decided to provide salvation sufficient for all, and God decided to elect some to receive salvation. The difference with infralapsarianism is in whether God first chose to provide salvation and then chose some to be saved, or the other way around.
The third term, supralapsarianism ("under the lapse"), gives the order as follows. First, God decreed some people to experience salvation and others condemnation. Second, He decided to create both kinds of people. Third, He chose to permit the fall. Fourth, He decreed to provide salvation for those already elect.
We find infralapsarianism best aligned with the Bible. We don't believe God is shown in Scriptures to have created people for condemnation. That said, what is important is not these delineations, but that we proclaim the saving power of Jesus Christ to those who need to hear and respond to it.
What is the doctrine of predestination?
What is the connection between predestination / election and foreknowledge?
Is the concept of double predestination biblical? Does God create some people for the purpose of sending them to hell?
Is unlimited atonement biblical? Is the atonement provided by Jesus Christ unlimited?
Sovereign grace – What is it? What is irresistible grace?
Truth about Theology