The Roman Catholic Church not only does not teach the doctrine of Assurance of Salvation - D Martyn Lloyd Jones

“The Christian is a man who should have assurance; it is the business of every Christian to have assurance… The Roman Catholic Church not only does not teach the doctrine of Assurance of Salvation, it preaches and teaches against it. Why? The explanation is quite simple. As long as you are uncertain, you are dependent upon the Church, you are dependent upon the priests. If you have assurance of salvation you do not need a priest, you do not need the help of the Virgin Mary, or the works of supererogation of the saints; you go directly to God through Christ. Assurance of salvation militates against the whole policy and activity of that Church with its teaching about purgatory and need of indulgences and so on; so they denounce that doctrine. That is, of course, because they put their own tradition before the Scripture, indeed because they here deny the plain teaching of the Scripture. They are thoroughly unscriptural and they can only establish their whole system, and keep it going, in defiance of the Scriptures.”

- D Martyn Lloyd Jones
Romans – Assurance