If you are like me and came from a traditional church background that included lots of hymns, you were probably taught at some point or another a style of congregational accompanying that roughly followed these rules.
1) In the right hand, add the tenor note to create a full chord and double the melody to create an octave.
2) In the left hand, alternate between low octaves and playing the full chord in the octave below middle C.
This style is often called “hymnplaying” in conservative circles. I call it sanctified stride because it is a an offshoot of the period it was developed in: early ragtime and the early form of jazz piano that was called stride. The term “stride” is an allusion to the left hand striding up and down the piano. I call it sanctified simply because it is a non-jazzy version of stride, missing a lot of the rhythmic elements that stride pianists back in the day utilized.
There is a place for that style of music in congregational singing so I am not going to put it down. It is in fact the basic style I teach in my course Congregational Accompanying. However, it would be a mistake to think all church music that pianists play should be in that style. Sanctified stride really only belongs in the setting of congregational accompaniment and perhaps a few other applications.
Because it is usually about all that is taught to aspiring church pianists, I often see elements of the style used in less than ideal situations. For example, if you are arranging for piano, be careful. Those thick right hand chords may seem impressive because they have lots of notes but you are sacrificing a lot of style points when you use them.
Here is a one bar example. Note the octaves in the left hand and the full chords in the right hand.
Again, there is a place for this sound but I would avoid it in a stylistic arrangement. What you want to do instead is balance the notes better between the two hands. Ditch the octaves in the left hand. An octave simply means the left hand is playing only one note of the chord (twice). It is not carrying its weight in the harmony. Move a note from the right hand to the left hand and play fifths, sevenths or tenths instead.
Here is the same bar with the chords balanced and voiced better. Play the bar both ways and listen to the difference.
As a general rule, if you are playing a four note chord, give two of the notes to the left hand and two notes to the right hand and spread out all the notes as much as you can. That is what we call open voicing and is a much better sound than the clunky hymn playing style.