Your question is ambiguous. If you want to find the very first instance
</verse-sub-section> in the entire file, and replace it with
then see the other answer(s). My interpretation is that, given the input
2 <verse-sub-section>In the beginning, God ...</verse-sub-section>
3 <section>Psalm of David</verse-sub-section>
4 <verse-sub-section>David Weeps</verse-sub-section>
you want to replace
</section> on lines 1 and 3.
If that's your question, the answer is
sed -i 's#\(<section>.*\)</verse-sub-section>#\1</section>#' file
<section> in the old field of the
s/old/new/ command guarantees that only lines containing
<section> will be processed.
\(…\) delimits a part of the line: the part starting with
and going up to (but not including) the
\1 in the new field causes the identified substring of the matched string
to be inserted back into the file -- i.e., left untouched.
At least that's how it works in normal versions of *nix.
Android shouldn't be any different, but I can't guarantee that it will work in busybox.