My salvation is secure because Jesus Christ has accomplished his work. That is what Scripture teaches. It is absurd to say that I am incapable of committing a sin that constitutes rejection of that grace, and Scripture does not teach absurdities.
13When you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him,
having forgiven us all our transgressions, 14having canceled out the certificate of debt consisting of decrees against us, which was hostile to us; and He has taken it out of the way, having nailed it to the cross. Colossians 2:13-14 NASB
What sin can you do that has not been canceled out, taken out of the way and nailed to the cross??