Gospel uses a powerful uplifting mood by using a positive tone.  That tone comes from a Allegro sometimes andante tempo it also comes from common strong instruments like drums, hand clapping, Piano/Oregon, Guitar and etc. 

Also to create that kind of tone you have to have a polyphonic texture, in gospel theirs four different voices one main singer leading their accompaniment and the three groups of accompaniment the sopranos high notes the altos in the middle and bass the low deep notes which are usually men. 

Most of the time in a song the most of the words are not repetitive but in a Gospel song the phrases in the song are going to be repetitive, this is because Repetitiveness carves out a familiar, rewarding path in our minds, allowing us at once to anticipate and participate in each phrase as we listen. So it makes us feel more connected to ourselves and connected to others.