“But exhort [encourage] one another daily, while it is called Today; lest any of you be hardened through the deceitfulness of sin.” (Hebrews 3:13, KJV)
Do not underestimate the power of personal example.
Sin is deceitful (e. g. tricky) because it always promises much and delivers little. Fellow disciples who are immature, inexperienced, or ignorant of God’s word are prime candidates for sin’s deceit.
Sin blunts the power of God’s spirit within us because it causes our heart to become less receptive (e. g. hardened) to both the Spirit’s guidance, and to the Spirit’s gifts. The farther we are from God, the smaller God seems. The antidote to this kind of atrophy is the “exercise” of growing ever closer to our heavenly Father.
We can be of immeasurable help to others at risk of sin’s deceit; and to those at risk of becoming hardened to the Holy Spirit’s guidance and gifts, by using every opportunity — every day — to testify (e. g. give voice) to the active presence and the loving care of our heavenly Father through our personal example. – Luther