Sentence:  [VV]e are able with playne demonſtration to <WSD>proue</WSD>, and vvith reaſon to perſvvade that in tymes paſt our fayth vvas alike, that then vve preached thinges correſpondent vnto the forme of faith already published of vs, ſo that none in this behalfe can repyne or gaynesay vs. 
Meaning of the word marked with <WSD> tags:  To demonstrate that something is true or viable; to give proof for.