Watch the Higher Ground - 7 online guitar lesson by Richard Kiser from Gospel Fingerstyle Guitar
This ending riff is sort of a signature "Chet Atkins" riff. It is simply a "pull-off" which means you play first note on the 1st string 3rd fret with your middle finger and while it is still sustaining, you pull the fretted finger downward and off the fingerboard as you are holding your index finger on the 2nd fret. Then do the same with your index finger pulling it off the fingerboard to allow the string to ring open. Thus; you pluck the string once and pull off the next two notes. Do the same on the 2nd, 3rd, and 4th string and then play the 5th string to resolve the riff, as well as the song. This pull-off can also be played the same way using the ring and middle finger instead of middle and index. Practice it slowly until it flows freely and each note is clear before you start working on speed.