Hebrews 3:12-13 (12 Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. 13 But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. ) That may be the verse many in the evangelical institutions stumble over through faulty interpretations. Sin has a way of deceiving and hardening the heart in making a person feel that they're not qualified to be a son/daughter of God and to take part of Christ, which is a deceitful lie from the flesh and the devil. That's why it says to exhort one another daily, exhort one another daily in who we are in Christ what He has accomplished, that our sin has been taken care of and removed as far as the east is to the West. Keep this in mind least our hearts be hardened and deceived by sin making us believe that were not qualified to be called a child of His as sin brings accusation. If we exhort each other in what Christ has done what He has accomplished, sin cannot bring its accusation and deceive us through its deceitfulness in hardening our heart toward a graceful merciful God.