The father of a seriously ill toddler told a court his son looks him in the eye and "needs help" as he fights a decision to end the boy's life support.
Tom Evans, of Bootle, Merseyside, wants to take son Alfie abroad for treatment.
Doctors at Alder Hey Children's Hospital have told the High Court further treatment would be "futile".
Earlier the court heard that the undiagnosed condition has destroyed more than 70% of Alfie's grey matter.
The case, being heard at the High Court sitting at Liverpool Civil and Family Court, is in its second week.
Mr Evans, 21, who is representing himself, and Alfie's mother, Kate James, 20, want to take the 20-month-old to the Vatican-linked Bambino Gesu Paediatric Hospital in Rome for treatment which may prolong his life.
But the boy's medical team at Alder Hey Children's Hospital believe that to continue life support would be "unkind, unfair and inhumane" and said the ventilator that helps him breathe should be withdrawn.
Mr Evans questioned one of the consultants who is caring for Alfie, who cannot be named due to a legal order, saying he was asking from a "Catholic point of view" if she believed in God.
She replied: "I don't think it's relevant."
The doctor was asked by Mr Evans why she "did not respect" his and Alfie's mother's opinions about their son's treatment.
She replied: "We are Alfie's doctors... not his parents.
"We put tremendous effort in, even in the most difficult circumstances, to try to get every child through. None of us wants to see a child die."
Mr Evans later said: "We see Alfie as a sweet, lovely boy.
"He does have a personality, he does share his emotions. We see potential, we see life."
The medic told the court: "If I felt there was hope for Alfie, chance for him to recover, chance for us to get him off the ventilator, I would absolutely not be here. We do not give up on children."
The hearing was adjourned until Wednesday.