、。
Words and actions should match, but it's difficult to follow through.
Literal
Words [and-と] actions [topic-は] be-consistent [should-べき] thing [copula-だ][but-が], execution [topic-は] difficult.
~べき 'should, must (by moral/logical obligation)' attaches to dictionary-form verbs, giving a normative tone more forceful than ~ほうがいい. The construction [verb]べきものだ 'is a thing that should be V-ed' further emphasizes the normative force by nominalizing the obligation. 一致する 'to be consistent, to match' takes a subject in the form [X と Y は] — X and Y together are the topic. 言葉と行動の一致 'consistency between words and deeds' is a traditional aphoristic theme.