All the time we hear that all Muslims should get united. But at the same time, we hear these words, "Arab Muslims", "Arabs and Muslims", 'Arabs' and 'Muslim world'. How can we tell our children and other people that Islam does not prefer one race over as other, since we see these phrases all the time? It is very hard for me to digest it. Is the word Muslim not enough? We always hear from our Arab brothers, that Arab and Muslims, like these are two different things. How can Muslim scholars and Imams address this problem? Should they preach on their speeches and on their web site about this very fundamental problem? I do not think, we can have any unity.

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Islam and Muslims are the two components of this religion. The religion that Allah has chosen for mankind as a comprehensive and complete way of living Allah Says (interpretation of meaning): {I have chosen for you Islâm as your religion.}[5:3]
Honour and dignity are for the Muslim and the Muslim alone as the name Muslim is given by Allah. Allah Says (interpretation of meaning): {It is He (Allah) Who has named you Muslims both before}[22:78].
We Muslims receive our religion from the Qur'an and from the Sunnah of Allah's Prophet. We are certain that there is nothing in the Qur'an or the Sunnah that gives any particularity for Arab Muslims over non-Arab Muslims. In fact the general rule is defined by Allah {Verily, the most honourable of you with Allâh is that (believer) who has At-Taqwa [i.e. one of the Muttaqûn (the pious)}[49:13]. The Prophet said: "Allah has freed you from the arrogance of the Jahiliya (pre-Islamic era). You are all children of Adam and Adam is from earth (dust)". [Abu Dawood and Al Tirmizi].
As for the expressions you mentioned Arabs/Muslims… they are from the call to Jahiliya. They do not emanate from a faithful Muslim. These are nothing but calls of extreme nationalists. These caller place the nationalism on the same level with the religion. But faithful Muslims who have accepted Islam as their religion and the Prophet Muhammad (Peace and blessing be upon him) as their messenger and Prophet avoid such calls. So all believing Muslims should accept only that which is evident from the Qur'an or the Sunnah and nothing else. So, we agree totally with your point of view and we ask Allah to provide for this Ummah some Du'a at who will explain to the people their true religion free from extremism, nationalism and all other non-Islamic calls. Allah knows best.