Are we to serve endlessly?

[AnthroHeart]

I forgot which thread I read it from but there was a passage that says that we stay incarnating in 3rd density until 4th density graduation. I had no idea this was the case until today. If that's the case then it makes sense that we've been incarnating here for a very long time (I know I have) and that the passage in LOO about being swept up in karma makes us being here as wanderers much more dangerous a mission. If you don't graduate then you essentially lost your 4th, 5th, 6th density progress from other lifetimes.

Ra also said that we are surrounded by an energy field of our home density. So we don't lose that progress. We just have to graduate to 4D in order to re-establish our home density.
If we miss it this time, we can graduate next harvest, and still go back to home density. We don't lose billions of years of evolution.