The growing problem of doubt.

Hebrews 3:12-15 ESV Take care, brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God. [13] But exhort one another every day, as long as it is called “today,” 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. [15] As it is said, “Today, if you hear his voice, do not harden your hearts as in the rebellion.”