Infancy, Disability, Salvation, and Sovereign Grace

"Will my son go to heaven?" The father choked out the words as he talked about his child with profound intellectual disabilities. The boy could barely communicate about his basic needs and had no ability to articulate an understanding of the gospel. What would you say to this father? Or to parents who have experienced the death of a baby? Section 8 of the Desiring God Affirmation of Faith points to why I affirm that the grace of God covers babies who die and people with profound or severe intellectual disabilities