on what the Buddha taught
Saddhā is often translated as faith.
The dictionary gives for saddhā but one word: faith. There are a few other words used in translations but when it comes to f.i. the saddhānusārī ("faith-follower" a stream-enterer underway to fruition, SN25.1) faith is used.
Now faith is mutually exclusive with knowing and understanding. As a stream-enterer knows and understands it is thus a bit odd to assign faith here. One wouldn't be even open to the teachings without some kind of faith or trust, but when it is understood then there is no doubt about it.
That there is then no doubt about it now that is with the strength of saddhā (SN48.44). And saddhā can come from wisdom (SN48.45). Thus if faith has room for doubt then saddhā can't be it. So, when you have no doubt about it, what do you have? To stay close to faith I opted for confidence. When one knows and understands one is confident. Confidence can come from wisdom but it can come from faith or belief as well. In one case there is no doubt and in the other case there is no room given to doubt, thus so for the strength of confidence.
Saddhā (f.) confidence.