What it shows that either the texture is too advanced (too thick) or the tempo is too fast or both.
Let me ask you this: would it be easier to play such hymn or a piece with one hand only, playing a single line only, say a tenor? Most people would say yes. And that's the answer!
Play your hymns at first not with both hands but with one voice, any voice. In fact, be very systematic and go through your hymnal playing a number of hymns just the soprano line with your right hand, then the alto with your right hand, then the tenor with your left hand, then the bass with your feet. Then all the two-part and three-part combinations before attempting to play all four parts.
But even then you may need to slow down a lot. Remember that the slower you play, the faster you will progress.
I know it sounds too simple to be true. But simple doesn't mean easy.
It's hard. In fact it's so hard that many people lose interest after 3 days playing like that. And it's hard not playing like that, but forcing yourself to sit on the organ bench for this kind of practice. But some people do succeed. Will it be you?
And one more thing - in order to play the chords easier you have to be able to understand them. Therefore, it would be wise to gain some knowledge of chords, their inversions, keys, modulations, harmony, voice leading and other music theory concepts.
It's like understanding the language you are trying to speak. You can learn to recite a poem in Japanese with a proper pronunciation but without understanding the meaning of the text it's kind of pointless, isn't it?
(And when you do understand the meaning of the text, wouldn't you want to communicate with this language?)