Yes, of course, the Church will continue to exist until the end of time. Yes, of course, evil and the devil cannot destroy the Church, however it tried for the past two thousand years. So some of us say, leave the Church alone. She will survive. She will overcome. We don’t have to do anything.
To me this attitude sounds self-complacent and triumphalistic. Although the survival of the Church does not depend on us, there is something we must do. We have to help others to know, to understand, and to experience the mysterious presence of Christ in the Church. Personal experience of Christ’s presence is possible through enlightenment and faith. An enlightened faith is possible through consistent study of Church’s teachings and frequent reception of the Sacraments. And this is possible only through humble and persevering prayer.