What is needed for creationists to connect evidence to valid conclusions

To reiterate Percy's Einstein point - If we were having this discussion 150 years ago, I might in a similar vein argue that Newton being right about gravity would mean that it made it more likely that his wackier beliefs (religious and alchemical) were true. This wouldn't actually be the case. But also, it now transpires, that Newton wasn't right, not all the time - so it would be doubly a mistake to believe something because we hold another view from the same source to be true: 1) The link is unwarranted and 2) even if it was, how can we be sure that the view we trust and use to draw conclusions about the other point's truth from is actually true in the first place?