I am not perfect. Do I use my own experience to discern the word of God, or does the word of God discern my experience, and judges me accordingly?
The word says 'be perfect as your heavenly Father is perfect', and it says 'I write this to you so that you do not sin'.
The word tells me that through Christ, I can overcome, so I believe it and cling to Christ, who is my hope, so that I might find deliverance and be like him. He commands to to overcome, and so I seek to do so.
The word also tells me that in our immaturity, we fall. It says 'if any of you sin, we have an advocate with the Father'. And so I believe it. It tells me that if I, now made alive by the Spirit, would walk by the Spirit, I would not fulfill the deeds of the flesh. And so I believe it also.
Jesus says 'No learner is greater than his teacher, but when he is fully trained he is as his teacher.' So I believe him also.
Am I justified by my belief? In no way. I have faith towards Christ that if I persevere and hold on to the words he has given me and to his promises, he will be faithful to have mercy and to make me as he is. Only I have no faith in my own ability to stay faithful, knowing that I can fail, and so I beseech the one who called me to give me strength.