My annotated noted on Hebrews 3:12-14. Being faithful until the end of life.
12 Be careful, brothers, lest there be in any of youp an evil heart of unbelief in departing from the living God.
[The slow slide into unbelief is a danger to all believers. There is the danger of something becoming a higher standard than the Bible. It may be science, philosophy, reason, emotions, spiritual experiences, love of something sinful, pride, forgetting to read and study the truth (Bible) every day. It may be a drawing away by politics, social action, problems, difficulties, illness, depression, etc. We continually need all believers to encourage us and rebuke us if necessary. Continually choosing other authorities (science, authority figure, government, etc.) and neglecting truth can lead to departing from God].
13 Urge one another every day while it is still “Today,” lest any of youp become hardened by the deceitfulness of sin.
[Hardening is a callus. Repeated use of any object leads to the skin becoming thicker. Repeated use of sin leads to a callused heart. Sin is deceitful because it seems pleasurable but practicing sin becomes an addiction which leads to overwhelming problems spiritually, emotionally, intellectually, physically, socially, etc. Compare Israel’s history as in Psalm 78:40. See Jeremiah 17:5, 9, and James 1:14].
14 For we have been made partakers of Christ, if we hold on to the beginning of our confidence firmly to the end.
[The Greek word for partakers is μέτοχος métochos (G3353). It means to share in something, a partaker. Compare Luke 5:7. The Greek word for hold is κατέχω katéchō (G2722). It means to firmly grasp. Compare Matthew 21:38. This is a conditional sentence—IF. The “if” is to have a will to continue in the faith. We do not want to fall away from the faith (Hebrews 3:12). We do want the assistance of our brothers and sisters in the faith (Hebrews 3:13) and want to persevere in the faith (v14). God’s grace continually assists us. Compare Luke 8:15].