One may have faith and evidentiary proof together; prosecuting attorneys do that all the time. It would be a terrible thing if they prosecuted people they believe innocent. They should need some faith in the guilt of the accused. I believe Democrats working the impeachment proceedings are an example of faith in the culpability of President Trump while they seek to build evidentiary proof. It does not mean that if Rep. Shiff has faith President Trump is guilty of impeachable offenses that he therefor has no proof (well, there may be exceptions to the rule), or that to have proof of the President’s impeachable offenses means that Democrats need have no faith in that (or maybe it does).