“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 more than it ever actually delivers. 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 the Spirit’s gifts. The farther we are from God, the smaller God seems. The antidote to this kind of atrophy is the disciples’ “exercise” of growing ever closer to our heavenly Father.
We can be of immeasurable help to others at risk of sin’s deceit and insensitivity to the Holy Spirit’s guidance and gifts by using every opportunity to testify (e. g. give voice) to the active presence and the loving care of our heavenly Father in our personal example of what we do and what we say. – Luther