Take care, brethren, that there not be in any one of you an evil, unbelieving heart [c]that falls away from the living God. 13 But encourage one another day after day, as long as it is still called “Today,” so that none of you will be hardened by the deceitfulness of sin.
Verse 12 gives the statement that there ought not to be an unbelieving heart. Verse 13 gives the antidote. The call is to “encourage one another day after day” with the reason being stated as “so that none of you will be hardened by the deceitfulness of sin.”
Fellowship, Biblical fellowship that is, is a means of God’s grace against unbelief. It is probably not often thought of it in that perspective among those who are engaged in apologetics. But it definitely states it in Hebrews 3:12-13.
Off to church now to be encouraged and encourage others’ faith!