If you consider these, you will find that each one of them is a very definite duty. We know, for example, that prayer involves five compulsory prayers everyday and night. Each one of these has its time range, number of rak'ahs, definite form, etc. There are other Islamic duties which are very important, but not so definite. They have not been included among the pillars of Islam.
Education is very important to any community.
There is no doubt about that. Islam is a religion which appeals to all communities, no matter what degree of advancement they have reached. It can be practiced in a primitive community and in a most sophisticated and advanced one. The relationship between education and Islam is mutually supportive. The higher the standard of education in a Muslim community, the better that community knows and defends its faith.