Watch the I Believe online guitar lesson by Stephen Bennett from Fingerstyle Finesse
Another reason I picked this tune is that it has a strong backbeat in it. This means an emphasis on beats 2 and 4. I grew up playing in rock and roll bands and the backbeat was very important. Often it would be mainstay of the drummer's snare part. This emphasis is an important component of my playing. I guess I am often looking for as full a sound as possible in my tunes; I want to hear melody, bass line AND some hint of percussion driving the music.
Speaking of the bass line, I Believe also is an example of a fingerpicking tune which does not rely on alternating bass. The bass line is something like what an actual bass player might play.
Again, with the D major chord that is formed with the 12th fret harmonics and the F# on the 6th string at the end of the main melodic phrase, we have an example of harmonics being integrated into a melody.
Another compositional idea worth mentioning here is that of secondary melodic parts. Note the little answering phrase to the main melody.
If the melody is A C E, then the answering phrase is A C G.