The words "aggressive submission" seem like they don't fit together, like it isn't a posture that any believer should take. However, when you understand the cross and the posture that Jesus took, they fit together perfectly.
In perfect submission to His Father and Their plans for all mankind, Jesus aggressively pursued the path to the cross. He was determined with all of His will to allow nothing to stop His purpose for coming into this world.
Now it's our turn. We are to aggressively submit to Jesus and the work of the cross. Along the way we might consider "unrelenting love" and "dying to ourselves" so that we might really live. Silly phrases to some, overcoming power to others!