This convenience seems to be about focus.
The convenience writer suggests that we have everything we need (mind, heart, and soul), and that we can focus on that fact to go about building a future more in line with our dreams.
The writer tells us to use what we have.
Convenience Four
Put Things in Their Places
We have a mind and a heart and soul ready for use in the right place,
and that are good by themselves and the rest should go.
Throw the rest out of reach