That I might know (εις το γνωνα). Paul's common idiom (verse 1. Thessalonians 3:2), εις το and the infinitive of purpose (second aorist ingressive active of γινωσκω, come to know).

Lest by any means the tempter had tempted you (μη πως επειρασεν υμας ο πειραζων). Findlay takes this as a question with negative answer, but most likely negative final clause with μη πως about a past action with aorist indicative according to the classic idiom as in Galatians 2:2 (μη πωσ--εδραμον) and Galatians 4:11 after verb of fearing (Robertson, Grammar, p. 988). It is a fear that the thing may turn out to be so about the past.

Should be (γενητα). Here the usual construction appears (aorist subjunctive with μη πως) about the future.