Colossians - Jesus has done everything (pt2)

Colossians 1:13-23 - an epic and most used passage about who Jesus is. But we can take it just as a nice list of things about Jesus, place them on our mental mantelpiece and then move on.
OR
We could start asking the question - Why has Paul written this here? I am learning to ask the best question ever - why?.

In the book (and its now a film) Eat, Pray, Love, Elizabeth Gilbert expresses her view of what she means by God. -

“In the end, what I have come to believe about God
is simple. It’s like this – I used to have this really
great dog ... She was a mixture of about ten
different breeds, but seemed to have inherited the
finest features of them all. She was brown. When
people asked me, ‘What kind of dog is that?’ I would
always give the same answer: ‘She’s a brown dog.’
Similarly, when the question is raised, ‘What kind of
God do you believe in?’ my answer is easy: ‘I
believe in a magnificent God.’ (Eat, Pray, Love, Elizabeth

Gilbert p. 15)"

Yet this leaves me feeling slightly disappointed. Surely God is more then just "magnificent"? Its very impersonal and doesn't cover the scope of who God is. Of course He is magnificent. But Paul is saying He is more then that in Colossians... in fact the answer to the resounding "why", is that Paul is showing that Jesus has done everything, He has completed everything and without Him what hope could there be?

Why would you ever go after a different Gospel if everything has been completed in Christ?
Why would you add on to the Gospel if Jesus has done everything?

Therefore if we are to be confident in Christ, it should change the way we share Him with our friends.

I hope it means I am not ashamed of Him and can be bold in sharing Him and know fully in my heart that I don't have to add on my works to what Jesus has done! It is good news.