Quote Originally Posted by Kraco
Ging doesn't seem to care that much right now, having lots of faith and trust in his kid, but if Hisoka killed Gon in a fight, things might be different. He could actually fight and not slip out of the confrontation. Naturally we as the audience know we will never see that, but from Hisoka's pov it's a possibility.
Ging is a fatalist. If Gon survives this, then he's naturally strong enough to. If he dies from this, then he's simply not worthy of being his son. The same goes for Gon surviving against an encounter with Hisoka.

Ging just left Gon as a baby and thought "My son will grow up nice and strong because, you know.. he's my son."