Ephesians 5:1-2 - Imitating GOD!

Ephesians 5:1-2 starts with, "Therefore..."

Having outlined God’s sovereign grace that dramatically saved these Gentiles (chpts 1-3), Paul goes on to describe how their lives should be dramatically different from what they were previously (chpts 4-6).  Paul's first word of command is that Christians should "imitate God."  What does that mean, and what does it look like?