yosef asks:
What does it mean and why is it so important? And if possible, how does one work on this.
thnx!
yosef,
The Kollel replies:
The Gemara in Yoma (72b) explains that this refers to someone who learns Torah but has no fear of Heaven. I think this answers your other questions as well (fear of Heaven is essential, learn Mussar etc.).
All the best,
Yaakov Montrose