A New Creation

Our old history ends with the Cross; our new history
begins with the resurrection.

"If any man is in Christ, he is a new creature:
the old things are passed away; behold they are
become new. (2 Corinthians 5:17)

The cross terminates the first creation, and out of
death there is brought a new creation in Christ, the
Second Man.
If we are in 'Adam' all that is in Adam necessarily
devolves upon us; it becomes ours involuntarily, for
we have to do nothing to get it. There is no need to
make up or minds to  lose our temper or to commit
some other sin; sin comes to us naturally and despite
how much we try to be good. In a similar manner if
we are 'in Christ' all that is in Christ comes to us by
free grace, without effort on our part. It is on the
ground of simple faith.
It is a four step process.
1 Knowing
2 Reckoning
3 Presenting ourselves to God,
4 Walking in the Spirit. (Watchman Nee)

Does this sound a bit complicated?
How does it work out in life?
Above all, does scripture back it up?