For the assertion that "There is no God" is just as much a claim to knowledge as is the assertion that "There is a God." Therefore, the former assertion requires justification just as the latter does.
William Lane CraigBut the Bible says that the unreached will be judged on a quite different basis than those who have heard the gospel. God will judge the unreached on the basis of their response to His self-revelation in nature and conscience. The Bible says that from the created order alone, all persons can know that a Creator God exists and that God has implanted His moral law in the hearts of all persons so that they are held morally accountable to God (Rom. 1.20; 2.14-15). The Bible promises salvation to anyone who responds affirmatively to this self-revelation of God
William Lane CraigBut the argument is still unsound, because the first premise is false: there are other unmentioned alternatives, for example, that Jesus as described in the gospels is a legendary figure, so that the trilemma is false as it stands.
William Lane Craig