No need to argue them as there is a tension in exhortation to continue in the faith and the fact the Jesus is able to save to the uttermost.
You are making a false dichotomy,
No I'm not. Under Grace said believers do not perservere. I and the Bible say the do. The Bible does not have false dichotomies, and I have said nothing that I have not or can not back up with scripture. Correctly exegeted scripture.