Hebrew 3:12-14:

12a Take care, brothers, 12b lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God. 13a But exhort one another every day, 13b as long as it is called “today,” 13c that none of you may be hardened by the deceitfulness of sin. 14 For we have come to share in Christ, if indeed we hold our original confidence firm to the end.

This passage begins in 12a with an imperative command to “Take care!” or “watch!”  The reason for the command is given in the the second half of verse 12: so that there won’t be of us that have an evil, unbelieving heart, which would lead to apostasy.

The writer does not leave us in the dark as to how we are to apply the command and avoid this gravest of all dangers.  Verse 13 gives us the manner by which we are to “take care”:  exhort/encourage one another every day.

The writer also gives us a temporal condition for this command: as long as it is called today.  This condition comes from the previous context of Hebrews 3:7 which draws from Psalm 95:7.  By pointing to the Psalmist’s use of the word “today”, the writer does two things.  First, he highlights contemporary relevance, giving an all inclusive condition, emphasizing that we are to do this all the time.  Second, the writer looks forward to the consumation of all things, the beginning of tomorrow, when fates are finally sealed and the battle for souls is over, emphasizing that we are to do this while we still have time.

For good measure, verse 13c brings our attention once again to what is at stake and why we are in need of such a demanding program.  The writer reminds us that this strict perscription of daily exhortation/encouragement serves a very important purpose:  so that none of us will be hardened by the deceitfulness of sin.

How do these warnings of apostasy find congruence with other biblical passages which give us assurance that none of God’s children will be lost or fall away?  The next verse, verse 14, gives us significant help with this apparent dillemma.  The ultimate evidence that we have become sharers in Christ, is that we hold our original confidence firm to the end. Moreover, it seems that this the ground for the previous commands.

Ponder the significance of this.  If we come to share in Christ and are a children of God, he will cause us to hold fast to our original confidence in the gospel.  God does this through providing means of grace in our lives to counteract the self-decieving, heart-hardening sin that would otherwise lead us away from God.  The means of grace highlighted in this passage is the church, not merely as an institution or formal assembly, but as honest friends and encouragers, brothers and sisters battling for each others sanctification and perseverence.  God has designed that our salvation is confirmed, that our sanctification is worked out, and that our perseverence is realized in authentic community, in which we live and die together in the gospel of Christ.