Yup. Taking communion once is not enough.
For that matter, nothing a Catholic does is enough. There's always more to add, more to do....
They tell us baptism saves, except that it doesn't. You have to add......
And so it goes....
The core issue here, and both honest Roman Catholics and Evangelicals can see it, is “OK, why keep going? why not coast?”
Well once you DO understand what Christ is and has done for and with you, it becomes silly to sit and coast. You’ve been endowed with God filled powers to run down the troops of hell. What are you going to do, sit there and sin? The bible does have a word for people in such a position and it’s not “unsaved” — it’s “shortsighted.”