Faith is the assured expectation of what is hoped for, the evident demonstration (footnote: Or "convincing evidence") of realities that are not seen.
Here is the Greek:
Westcott and Hort / [NA27 variants] Ἔστιν δὲ πίστις ἐλπιζομένων ὑπόστασις, πραγμάτων ἔλεγχος οὐ βλεπομένων·
Specifically, is "evident demonstration" (or "convincing evidence") an acceptable translation of ἔλεγχος? Other translations have "conviction" (e.g., ESV, NASB).