Precision is clearly called for. It’s quite unfair of you to oversimplify things and say that we Christians “encourage self-doubt” while you Buddhists don’t. Your childhood experiences with the total depravity crowd, while certainly unfortunate, do not entitle you to paint a whole religion in such terms.
As you must surely know, there are innumerable accounts in Zen of masters encouraging massive “doubt” in their charges and treating them very strictly, even severely, with a view to pushing them toward satori. On the other hand it’s possible for Christians to place their stress on the “other Power” of Christ in such a way as to remain utterly free from all feelings of personal unworthiness.
I’m reminded in this regard of the following excerpt from an interview with the “Little Flower”, St Thérèse of Lisieux:
“What would you do,” she was asked, “if you could begin over again your religious life?”
“I think I should do as I have already done.”
“Then you do not share the feeling of the hermit who said: ‘While a quarter of an hour, or even a breath of life, still remains to me, I shall fear the fires of hell even though I should have spent long years in penance’?”
“No, I do not share that fear; I am too small. Little children are not damned.”
Needless to say, this doesn’t mean we’re to go to the opposite extreme, throwing out doubt and substituting complacency. On the contrary the key is to continue demanding a great deal of oneself while nonetheless realizing that our efforts are as nothing in the face of the Absolute.
“No one,” it is said, “finds God by seeking Him. But only those who seek Him find Him.”
The spiritual life is deeply koanic in character. We must work as hard as we can (“work out your salvation with fear and trembling”), as if everything depended on us, while simultaneously reposing in the knowledge that everything depends on God (“for God is at work within you”). This is not a rationally resolvable puzzle; it can only be solved existentially. As I’ve said before in the pages of this weblog: Solvitur ambulando.