It is because he has bought a lie -- that a certain amount of belief in Jesus, with its natural and attendant chauvinism to that effect is sufficient for eternal salvation. The problem he faces in this view is very hard -- to give up that promise which he has entrenched in himself, while been told that the very belief is necessary and sufficient.
It might well be that this is the best he does for the time being, and the best we can do is to affirm the acts and words of the Christ in practice and word, while denying that chauvinistic interpretation and degradation of Christ and Christianity and further chauvinism of our own.
While I think I understand the difficulties in going beyond that chauvinism, the path ahead is also very clear -- to love God as not just the God for myself, but for others as well, and to appreciate that the globalization which is stronger now than ever before, is also a gift to us from God in this time, such that we can better see the need for harmonious attitudes and outlook, and better recognize that the word of God was not limited to a single time and culture, but pervades all time and all cultures, for all souls, and all the better deserves our love, sacrifices, and attention towards that end.