It's undeniable that education is one of the most important growths in human society. Society deems raising the next generation is a reflection first of the education system surrounding children. The process of learning is a gradual progression that unfolds as students mature. This process is accounted for in milestones or grade levels as a person ages. Also, girls tend to mature faster than boys, but this does not nessacarly mean that they are smarter academically. The brain fully develops around 25.
Kindergartners around the age of 4-6 should understand certain elements of life, but not be advanced in them yet. They should have a grasp on understanding time; be able to compare parents rules to other students, but not understand right from wrong yet; curious about real world facts; should understand commands with multiple instructions; string 6-8 words together in a sentence; know basic information on the mothers, weeks, money, and a few colors. Many religious children have increase manners, may sing church songs like 'This Little Light of Mine', and may have an increased respect for elders, parents, or teachers from rules and respecting God. They can also respect the rules they are given such as the 'Ten Commandments'. Finally, children that attend church are more used to attending classes like Sunday school or Wednesday night church so being in a classroom may not be too much of a shock.
Third grade year is a very crucial education year for students 8-9 years old. This is usually when when friendships of the opposite ganders are created. Kids in third grade should know that months and days of the week in order, understand the concept of space, can count backwards, and should be fairly chatty. Children that attend church should be learning wisdom and the ability to apply God's word to life situation. That want to seek out and install the truth with people. Stistcically religious third graders are behind the mental growth curve compared to non-religious third graders.
So this is late middle school early high school ages around 13-15. People of this age are usually experiencing lost of emotions and hormones. They tend to rebel a little more, but religious students will tend to still keep at least some respect for their elders. Since religious students still have respect for people like teachers and parents, they are more likely to learn and still have fun rather than just not pay attention. Thus, the teachers may favor these children and they may learn more since they're more receptive to the teachers putting religious students ahead in this age group.
People of this age are usually stressed, but understand how to communicate effectively. Religious teens tend to stay away from drugs, alcohol, and other behaviors. This is opposed to religious teens that tend to get into more trouble. As common as these things are though, I don't believe that they are as popular among teens as it used to be. There's things like life 360 and believe it or not, teens really do have consciouses. Many people are studying different things at this point to prepare for their careers and college, but both groups prove to be intelligent here.
Adults, even if they're 18, their brains are still not fully developed, as they finish developing around the age of 25. People of this age are clearly still learning, we all are. But they obviously know right from wrong and can keep themself's alive and fed. Although, similar to 11th and 12th graders, they are off in their own careers and studies, but religion does effect the way that they may go about or do things.