# Be rooted ... be built ... be established ... abound

These words explain what it means to "walk in him." Paul speaks of a person with true faith in Christ as if that person were a tree growing in solid ground with deep roots. 

# be built on him

Paul speaks of a person with true faith in Christ as if that person were a building that has a strong foundation.

# be established in faith

"trust in Jesus for everything"

# just as you were taught

"just as you learned" or "just as they taught you" or "just as he taught you"

# abound in thanksgiving

"be very thankful to God"