At the present time, your surplus will meet their need, so that in turn their surplus will meet your need. This way there will be equality.
KJV
But by an equality, [that] now at this time your abundance [may be a supply] for their want, that their abundance also may be [a supply] for your want: that there may be equality:
ASV
but by equality: your abundance being a supply at this present time for their want, that their abundance also may become a supply for your want; that there may be equality: