The Body grows without –

The Body grows without – 
The more convenient way – 
That if the Spirit – like to hide
Its Temple stands, alway,

Ajar – secure – inviting – 
It never did betray
The Soul that asked its shelter
In solemn honesty
F438 (1862)  J578

When Dickinson refers to the body as a Temple she is surely invoking Paul’s first letter to the Corinthians (6:19-20) where he says,

What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's.  

But Dickinson does not claim the body as a chattel object of the deity. It serves the individual Soul, sheltering it and always “Ajar – secure – inviting,” and absolutely reliable. 
         The body becomes a temple just in case the Spirit it houses (Dickinson is using Soul and Spirit interchangeably here) wants to hide. It’s a lovely inside/outside image. 
          The body is our external presentation to the world, but its secret function, temple to the soul, is more important. It’s as if there is a world contained within, great enough for even the vastest soul. That it is a temple reflects the poet’s belief that the interior world is more precious than the external. We understand that not all spirits “like to hide.”
        In the second stanza, we learn that the Soul  can’t just dash in and out as the mood hits. Instead, it needs to ask for the body’s shelter “In solemn honesty” as if taking a vow, becoming a priestess or priest who dwells within the secure and sheltering Temple walls.  
        I like how the body grows “The more convenient way,” using the building blocks of matter to create a physical edifice. I suppose, then, that the Soul’s development is less convenient. The cells don’t just divide and specialize and do their maturing routine. It grows somehow internally, hidden and mysterious.  Unlike St. Paul’s formulation, this body/spirit combination are self contained. The Holy Ghost is but another name for the spirit within.