Letting the old man die (or outright murdering him) involves not so much killing the lust or desire for things that cost more than you can afford or will never need as much as being aware that you can never take those things from this world, so perhaps an investment in something eternal might be more appropriate. Crucifying the old man involves not so much killing the jealousy that makes someone close to you keep themselves at arm’s length as much as being aware that true love always trusts and always hopes and always perseveres.
The kingdom of God is not place we go, it is a state of existence where we can discover the truth of God that will live on in our spirits forever. It is the place where we can leap into the air because of the joy found in us at the knowledge of the love of God. So get to leaping.