The Buddha did not call his followers Buddhists and in fact in at least one instance recommended that Buddhism be called vibhajjavada, which means “doctrine of analysis.” The followers would be called vibhajjavadins, which would basically mean “analysts” or “those who analyze.”
The Buddha's teachings are focused on the Noble Eightfold Middle Path which is characterized by Morality, Concentration, and Wisdom. All three are cultivated in the 8 fold path. There are many schools of Buddhism and many varieties all of which emphasize different aspects in practice, such as chanting, meditation, bodhisattva ideal, and prostrations.
The Theravada places a balance between the different types of practice with about an equal importance given to all the types including chanting / prayer (such as loving kindness prayers), meditation, generosity and helping others, and reading / studying and analyzing. Contrary to some belief, the Theravada does include an emphasis on compassion, generosity, and helping others, including aiding them in their attainments. There is just more of an equal footing given to individual attainments along with helping others and the other practices mentioned here.
The Theravada also acknowledges that progress on the Path is gradual, which is supportive of the gradual training involved with meditation and study. In the Pali Canon, Majjhima Nikaya, Kiagiri Sutta 70.22 the Buddha says:
“Bhikkhus, I do not say that the final knowledge is achieved all at once. On the contrary, final knowledge is achieved by gradual training, by gradual practice, gradual progress.”
The Buddha further talks about studying the dhamma, following the dhamma, having faith or confidence in the teachings by hearing it and memorizing some of it, and practicing it. In Majjhima Nikaya Subha Sutta 99.4 the Buddha says, “I am one who speaks after making an analysis.”
In several places the Buddha talks about making an investigation. Even the parts that refer to faith or confidence in the Buddha (as an enlightened one) or in the teachings, are only after an investigation of the teachings to see if they are good and make sense.
“Here, bhikkhus, when he makes a thorough investigation, a bhikkhu thoroughly investigates thus: ‘The many diverse kinds of suffering that arise in the world headed by aging-and-death: what is the source of this suffering, what is its origin, from what is it born and produced? When what exists does aging-and-death come to be? When what does not exist does aging-and-death come to be?’” Samyutta Nikaya 12.51
Upali lived during the time of Buddha and was the follower of another religion and went to the Buddha in order to argue with him and try to convert him. But after talking to the Buddha, he was so impressed that he decided to become a follower of the Buddha. But the Buddha said:
“Make a proper investigation first. Proper investigation is good for a well-known person like yourself.
Now I am even more pleased and satisfied when the Lord says to me: 'Make a proper investigation first.' For if members of another religion had secured me as a discipline they would have paraded a banner all around the town saying: 'Upali has joined our religion.' But the Lord says to me: Make a proper investigation first. Proper investigation is good for a well-known person like yourself." Majjhima Nikaya 2.379
The fifth part or book of the Samyutta Nikaya goes into detail about the 37 aids to enlightenment (which is like an outline of the way to enlightenment) and the most common mental factors found according to the lists and Buddhaghosa in the Visuddhimagga (Path of Purification) are investigation, mindfulness, and wisdom. This further shows the supremacy of completing an analysis and attaining wisdom in the Buddha's religion and a rejection of blind faith.
The Vibhajjavada school says that the first step to insight has to be achieved by the aspirant's experience, critical investigation, and reasoning instead of by blind faith. This school was introduced to Sri Lanka by the Venerable Mahinda, son of Emperor Ashoka, who brought with him the Pali Canon. Vibhajjavada is an ancestor of the school known today as Theravada.
In one discourse, the Buddha emphasizes the importance of meditation and study:
“There are dhamma-experts who praise only monks who are also dhamma-experts but not those who are meditators. And there are meditators who praise only those monks who are also meditators but not those who are dhamma-experts. Thereby neither of them will be pleased, and they will not be practicing for the welfare and happiness of the multitude, for the good of the multitude, for the welfare and happiness of devas and humans.” Anguttara Nikaya 4.46 The Buddha goes on to praise both dhamma-study and meditation. To this day, there are some groups who disparage the other, while in fact both study and meditation are important and praised by the Buddha.
The Theravada can be seen as the foundation of Buddhism with its origin to the time of Buddha and the equal importance given to all forms of practice. The other schools of Buddhism are not wrong and in fact are on the Path to enlightenment in the same way, they just emphasize different characteristics of the foundation more and specialize in one or more forms of practice, but do not reject the foundation.