# while we are in this tent

Paul speaks of the physical body as if it were a "tent." 

# in this tent, we groan

The word "tent" refers to "the earthly dwelling that we live in."

# being burdened

Paul refers to the difficulties that the physical body experiences as if they were heavy objects that are difficult to carry.

# We do not want to be unclothed ... we want to be clothed

Here "to be unclothed" refers to the death of the physical body; "to be clothed" refers to the resurrection body that God will give.

# to be unclothed

"to be without clothes" or "to be naked"

# so that what is mortal may be swallowed up by life

The physical body that will die will be replaced by a resurrection body that will live forever. 

# so that what is mortal may be swallowed up by life

"so that life may swallow up what is mortal"