When God judges believers, it is not a punitive judgement. Christ has already carried their punishment (see 1 Corinthians 5:7). Rather, the judgment is disciplinary. The verb discipline
comes from the sphere of childrearing. It refers to the (usually painful) process of training and correcting a beloved child.
God is disciplining the Corinthians by striking them with illnesses and death. This is an act of love, whereby he seeks to prevent them from becoming hardened in sin and falling under his eternal condemnation.
33 So then, my brothers, when you come together to eat, wait for one another