For example, it can often happen that you play correctly the 1st time, the 2nd time and you make a mistake on the 3rd time. Is that what happened to you in your organ practice?
That's OK. Failing and making mistakes is an integral part of our learning process. So please don't get frustrated when you make mistakes. In fact, if you don't make a mistake at the beginning stages of your organist training, then something is likely wrong with your organ practice.
If you don't fail enough times, you will not know what success is. If you feel you are not making any mistake at all, it probably means you are not looking hard enough and not concentrating on details (such as notes, rhythms, fingering, pedaling, articulation, ornaments, hand and feet position etc.). It probably means your mistakes get unnoticed.
If this is the case, record yourself and listen to your recording. Ask yourself, "would I pay money to get to this concert if someone played like that?".
Practice until the answer is yes. As they say, Practice Makes Perfect. Let's add to it Wise Practice Makes Perfect. Make sure you take a really slow controlled tempo in which you can think of the next note before you play it.
Practice in fragments of 4 measures as I always recommend (do 10 times each fragment) in separate voices and all combinations of 2 and 3 voices before putting everything together.
If you struggled with making mistakes up until now, apply these tips and in just 7 days, you will feel the breakthrough. If not, then it may mean that the piece is too difficult for you at the moment and that you need to work on your organ technique.
Force yourself not to look at your fingers and feet while you are playing. Look at the music. If you play from memory, just close your eyes. This is tough, I know. But trust me on this, it will get easier with time and the benefits of doing so are enormous.
By the way, do you want to learn my special powerful techniques which help me to master any piece of organ music up to 10 times faster? If so, download my video Organ Practice Guide.