The first step in learning to perform in the gospel genre is understanding its use of percussion (even if you are not a percussion performer, its rhythmic attributes pervade through all areas of the genre). The percussion instruments associated with gospel music (including the drum kit, the tambourine, and the piano) employ very active accented off-beats in their rhythms, and are thus generally associated with the most rudimentary origins of syncopation (commonly seen in jazz). Thus in the gospel genre, you will often hear a distinctive use of a tambourine, bass drum pedal, high hat, or even the left hand of the piano part consistently falling on the off-beat of a given piece.
The second step in learning to perform in the gospel genre is understanding the harmonic use of the piano (rhythmically, the piano has the same qualities of the percussion topic discussed above). The plagal cadence (I-IV-I), also called the "amen cadence," is perhaps the most common figure of the gospel genre, and is additionally seen all throughout the classical era (see the Tips section of this article for a rudimentary description of chord functions). Though additional harmonies do present themselves in gospel piano (such as deceptive resolutions, and the cadencial 6/4), the plagal cadence is by far the most important.
Once you have understood the harmonic use of the piano in the gospel genre, the gospel organ is additionally important for discussion (though often closely associated with the piano, it has a unique instrumental quality about it that calls for its own discussion). Capable of holding notes for long periods of time, the organ is commonly used in long, multiple-bar chord vamps, creating the pentacostal gospel style which is most often associated with "rural" gospel.
The vocal qualities of the gospel genre are perhaps the music's most defining qualities, and can be broken down into two separate points of interest: melodic styling and rhythmic styling. Melodically, the gospel vocal style is characterized by high, virtuosic vocal lines displaying the range of a single vocalist (most often female). Additionally, this vocal style is most commonly accompanied by some sort of "call and response," in which the solo vocalist will present a melodic idea, and a choir will respond to that idea with a second, often similar (if not identical) theme (for example, "God's gonna separate the wheats from the tares" sung by the soloist, followed by "Yes He will!" from the choir.)
Rhythmically, the vocal style of the gospel genre has two important points of interest (though it should not be assumed that these are the ONLY points of interest). The use of melismas, in which a changing melodic line is extended over a single syllable, is a common technique of the gospel genre. Furthermore, the use of complex rhythms, in which an odd number of beats is compacted into an even-numbered bar (called "three against two") is used to facilitate the use of melismas (see the Tips section for a more refined definition of "three against two").