Lyrics to old song: I Believe, some of the words are: I believe in every drop of rain that falls a flower blooms,

Many singers have covered I Believe. Since you mentioned old, here are the lyrics to Elvis Presley's version.
Elvis Presley - I Believe Lyrics (http://www.elyricsworld.com/i_believe_lyrics_elvis_presley.html)

Are you wanting a different version?