A.T. Robertson Commentary Romans 14:5

"One man esteemeth one day above another: another esteemeth every day [alike]. Let each man be fully assured in his own mind." — Romans 14:5 (ASV)

One man (ος μεν),

another (ος δε). Regular idiom of contrasted demonstratives (this one, that one).

One day above another (ημεραν παρ' ημεραν). "Day beyond day." For this use of παρα (beside) in comparison see 1:25; Luke 13:2.

Be fully assured (πληροφορεισθω). Present passive imperative of πληροφορεω, late compound verb for which see on Lu 1:1; Romans 4:21.

In his own mind (εν τω ιδιω νο). Intelligent and honest decision according to the light possessed by each.