2. Belief in the existence of Angels.
     Angels are not Allah's children. They were created before humans which is from light for the purpose of worshipping Allah. Furthermore, human are created to worshipping but human can eat and sleep. Nevertheless, angel doesn't sleep, eat or suffer from illnesses. 

     Apart from that, angels are created to record of our deeds, blowing the trumpet on judgment day, taking people's souls and be the keepers of heaven and hell.


3. Belief in the books of Allah.
    Allah revealed this books as a form of guidance and proof for mankind. This books was revealed to his messenger. For instance, the Quran was revealed to Prophet Muhammad and the Injeel was revealed to Prophet Isa.

As stated in Surah Al-Hijr, Allah has guaranteed the protection of the Quran from any distortion which is:

5- Belief in afterlife in the hereafter.

Afterlife means the living again in another life called hereafter which is the world  retribution and comes at the end of person's life-journey. Allah's prescribed 41 names of judgment days such as ‘یَوْمُ الْوَعِیْدِ’, which is the day of the warning of torment, and  ‘یَوْمُ الْبَعْثِ’ is the day when people will be resurrected.

In the day of judgment, one whose good deeds overweigh his evil deeds will prosper, while whose bad deeds outweigh his good ones will be condemned to hellfire unless he died in the state of Islam. Then, Allah would either punish him or forgive him, and eventually he would enter paradise.

Besides, address them with respectful would be adab to parents by which a children should talking to them softly and with love.

2- Adab with neighbors
 
Treating one’s neighbor with respect and duty. When asked what the rights of the neighbor are, the Prophet Mohammed answered: “The least of a neighbor’s rights on him is that if he asks him for a loan he should grant it to him. If he asks for help, he should help him. If he wants to borrow something from him, he should lend it to him. If he needs him to donate something to him, he should do so. If he invites him, he should accept his invitation. If he gets sick, he should go and visit him. If he passes away, he should attend his funeral procession.” [Mustadrak al-Wasa’il, v.2, p.79]

Besides, ones must not trouble their neighbor. It is already narrated in one narration which is,  someone complained to the Prophet Mohammed about his neighbor. The Prophet reportedly turned his face away from him, and then stated to those around him: “Go and publicly announce that the curse of God and the angels is on one who troubles his neighbor.” [Mustadrak al-Wasa’il, v.2, pp.78-79]. Therefore, it is important for us to have adab with our own neighbor.

3- Adab with teachers

In fact, I believe that the etiquette of learning is even more relevant and needed in this age to preserve the sanctity of knowledge and its inheritors

A student can't talk when the teacher is teaching due to not disturbing  teacher. Besides, one should talkingto teacher with respect because it will give return to us.

Ones should practices adab with teahcer as our ulama shows. For isntance, Imam ibn Hasan Asy-Syaibani described and praised Imam As-Syafie as a student who was calm and composed in his ability to ask questions respectfully and listened carefully when he faced opposing views. Besides, ones need to be humble when learning with their teacher. Even though Imam As-Syafie was reported to be gifted with a photographic memory that enabled him to memorize the Quran at the age of 7, he made sure that he wrote down everything he learnt from his teachers.