Rindu wrote:VERO isn't "truth" but just "truly" or "indeed." You are close. Some commas might help you:
Vero iter, quod ad sapientiam ducit, durum est.
Such use of commas may have been permissible at one time, but when we have a defining relative clause, as here, I think it makes things clearer, in both Latin and English, not to comma off the noun from the adjectival clause that defines it.