My friend, you are conflating justification with sanctification. I expect that with Roman Catholics, but it shouldn't happen on a Baptist forum.
We are justified- declared righteous by God- by grace alone, through faith alone. That is our salvation. Christ died not for good people, but for the ungodly (Romans 5:6).
We are also sanctified positionally by God alone. 'To those sanctified [perfect participle] in Christ Jesus' (1 Cor. 1:2). We are set apart by Him for the good works that He has pre-ordained for us (Eph. 2:10). However, our progressive sanctification also involves us. 'For this very reason, make every effort to add to your faith goodness.......etc. (2 Peter 1:5ff). But even here, we are upheld by God in those efforts. '......For it is God who works in you to will and to act according to His good purpose' (Phil. 2:13).
So whilst a Christian must endure, and must obey the commands of our Lord, we are promised that we will do so. If we are Christ's sheep, we will follow the good Shepherd, He will give us eternal life and no one will snatch us out of His hand (John 10:27-28); if we do not follow Him in obeying the Father's commands, it is because we are not His sheep, and He will say to us, "I never knew you! Depart from Me, you who practise lawlessness!" (Matt. 7:23), not, "I knew you once and then forgot about you!"
'Everyone who has this hope in Him purifies Himself, even as He is pure' (1 John 3:3). If there is someone who claims to be a Christian but has no interest in keeping His commandments, he is deceiving himself (1 John 1:6).
