Hebrews 3:12

Take heed

(βλεπετε). Present active imperative as in Philippians 3:2 (three times) of βλεπω in place of the more usual ορατε. Solemn warning to the Jewish Christians from the experience of the Israelites as told in Hebrews 3:95.Lest haply there shall be

(μη ποτε εστα). Negative purpose with μη ποτε and the future indicative as in Mark 14:2. But we have in Colossians 2:8 μη τις εστα as in Hebrews 12:25; μη occurs with the aorist subjunctive, and μη ποτε with present subjunctive (Hebrews 4:1) or aorist subjunctive (Acts 5:39).In any one of you

(εν τιν υμων). The application is personal and pointed.An evil heart of unbelief

(καρδια πονηρα απιστιας). A remarkable combination.Heart

(καρδια) is common in the LXX (about 1,000 times), but "evil heart" only twice in the O.T. (Jeremiah 16:12; Jeremiah 18:12). Απιστιας is more than mere unbelief, here rather disbelief, refusal to believe, genitive case describing the evil heart marked by disbelief which is no mark of intelligence then or now.In falling away from the living God

(εν τω αποστηνα απο θεου ζωντος). "In the falling away" (locative case with εν of the second aorist active (intransitive) infinitive of αφιστημ, to stand off from, to step aside from (απο with the ablative case θεου) the living God (common phrase in the O.T. and the N.T. for God as opposed to lifeless idols)). "Remember that to apostatize from Christ in whom you have found God is to apostatize from God" (Dods). That is true today. See Ezekiel 20:8 for this use of the verb.