Because people with clefts have missing bone, the topology of the face is completely different to a regularly formed person's. This still applies to repaired clefts, to what extent depends on the original severity of the cleft and the success of the surgeries + orthodontics.

(I am going to use the word "cleft" by itself several times for the sake of brevity, please know I am referring to maxillofacial clefts every time. Clefts can occur outside of the maxilla, where they are known as craniofacial clefts, I will not be covering those right now.)

I find diagrams like this to be misleading, as they present the cleft like a thin "cut" in an otherwise fully formed head.

This is a more accurate visualisation of the condition, a cleft is more like a "gap" or "chasm". Tissue, both soft and hard, that would've been present in this gap is missing completely. That's skin, bone, muscle, teeth, and everything else.

People with clefts will often have a bone taken from usually the hip to be added to the upper jaw, to substitute for the absent material. People with clefts are also often missing adult teeth. Cleft repairs take a very long time, and that's under accessible healthcare of relatively high quality. The missing bone in the upper jaw causes most with maxillofacial clefts to have underbites, because the upper jaw is too short. Underbite correction is often the very last major surgery to be carried out. It is often done in the early twenties, because bones have stopped growing in length by that point in most people's lives. It is important to pay attention to the age of your character with a cleft. I don't expect you to have planned out an entire medical history, but the structure of a face with a maxillofacial cleft changes dramatically throughout early life. I think the underbite is the biggest thing I want to see more in people's cleft characters; remember the underbite caused by a cleft is due to a short upper jaw and NOT a long lower jaw.

For unilateral clefts, the nostril on the side of the cleft is smaller than the other, unless the cleft stops a while before reaching the nose. The cleft-side nostril also often has compromised breathing ability, causing many with clefts to rely on breathing through the mouth instead. People who are still going through treatment can have a fistula connecting the inside of the mouth and the nasal cavity. This fistula causes trouble with eating and drinking, as material passes into the nose and food can clog the fistula up. On the bright side, it can allow for the very cool party trick of being able to drink through the nose or eject fluids through the nose from the mouth. The deformed shape of the mouth affects pronunciation as well, since the jaws don't align as they should, people with clefts have to "cheat" to perform certain sounds. The voice also often sounds nasally because of increased airflow into the nose.

Even though the clefts are maxillofacial, effects can extend to the ears. People with clefts often get frequent ear infections especially as children, some have a flattened ear canal on the side of the cleft, and some have impaired hearing and may require hearing aids.

Please do not remove his lip scar while drawing him. It's crucial to his design it's his cleft palate scar. It's IMPORTANT.

my grandma insisted that my cleft lip+palate was a result of my mom's "jezebel spirit" and that I was born as a curse to my father

there idea that deformities are demonic is still VERY popular and it makes me feel awful about myself

This is deformimisia. It genuinely breaks my heart that so many people with deformities have been considered "curses" of some kind across so many belief systems.

You don't deserve to feel this way about yourself. You are not a curse, your condition is a neutral characteristic. There is not some horrible, evil reason as to why you are the way you are. Deformities are completely devoid of any tyep of morality - not good, not bad, just there.

(I will say, as a schizospec, I'm unsure if this is really religious psychosis. There's too limited of information. It just sounds like bigoted religious beliefs, which doesn't indicate a person is going through pyschosis.