How Right Do I Need to Be About Theology to Enter the Kingdom?

Questions about how right a person’s theology needs to be to enter the kingdom, whether it’s okay to baptize a cognitively challenged person who isn’t able to explain salvific concepts, and whether an intellectually disabled person can be saved if they can’t understand the theology of salvation.   Considering there are a lot of Christians who say they’re right that don’t agree with each other, how “right” do I need to be to enter the kingdom? Is it okay to baptize a young man who really wants to be baptized but who has cognitive challenges and isn’t able to explain salvific concepts like God’s grace or why Jesus needed to die on the cross? Can my intellectually disabled daughter be saved if she can’t understand the concepts involved with Jesus personally dying for her sins?