In a previous Fatwa mentioned that Hizb ul Tahreer (a Muslim poltical group) are neglecting certain aspects of Islam i.e the spiritual, how can we solve the problems of the Ummah?

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.

No doubt, the Islamic system is a comprehensive, balanced system which meets the needs of soul, mind and body all at the same time. The Islamic system does not neglect the requirements of human soul, body or mind. The Prophet's teachings address them all equally. The companions followed the same path. In fact the Prophet was busy with many wars and conquests against the Kuffar but did not neglect the subject of morals. In fact it was he who educated and purified his companions as Allah Says (interpretation of meaning): {He it is Who sent among the unlettered ones a Messenger (Muhammad SAW) from among themselves, reciting to them His Verses, purifying them (from the filth of disbelief and polytheism), and teaching them the Book (this Qur'ân, Islâmic laws and Islâmic jurisprudence) and Al-Hikmah (As-Sunnah: legal ways, orders, acts of worship, etc. of Prophet Muhammad SAW). And verily, they had been before in mainfest error;}[62: 2]. Indeed, the Prophet said: "I was sent to complete good morals".
If a person reads the history of many South Asian countries such as Java and Sumatra he will find out that the residents of these countries became Muslim through interactions with Muslim business men who strictly followed the Islamic teachings, and no Muslim army was ever sent to those places. There are many other examples, which show clearly that the Islamic morals and Islamic teachings have been major factors in the spread of Islam. If a community or a group neglects or does not concentrate on the morals and on watching the behavior of its members and does not educate them according to the Islamic teachings, (i.e. "Tazkiyah Nafs", purifying them from all kinds of evil and habituating them to good acts), it deviates from the right path. Who dare saying that good morals and good behavior stand in the way of Dawa, and Jihad?
As for the fact that Hizb al-Tahreer neglects the spiritual matters, we would like to mention here some points concerning such issue.
1. We mean by spiritual matters, purifying the people from bad faiths, practices etc. and raising them according to Sharia.
2. What the Prophet did to establish an Islamic government in the world was a tremendous Jihad since it included all kinds of Jihad i.e. Jihad against desires, Satan and evils, Jihad with the sword and the word, struggling to elevate the true religion and demolish the Kufr.
3. As for the question what should we do to solve the problems of the Ummah? The answer for this question is that we should make Dawah just as the Prophet did and we should follow the steps of our good ancestors in understanding and implementing the Sharia. This can not be done by sitting. Dawah means making efforts to establish the Islamic rule in this world, spreading the truth, enjoining good and forbidding evil and guiding the Ummah according to the Sharia. This way is the way of the Prophet (Peace and blessing be upon him). Qur'an also treats both moral and physical diseases, just as it treats the diseases of intellect.
The Qur'an attributes disasters which took place in the battle of Uhud and Hunayn to being disobedient to Allah and His Prophet Muhammad. Allah Says (interpretation of meaning): {(What is the matter with you?) When a single disaster smites you, although you smote (your enemies) with one twice as great, you say: "From where does this come to us?" Say (to them), "It is from yourselves (because of your evil deeds)." And Allâh has power over all things.}[3: 165].
In another place in the Qur'an Allah Says (interpretation of meaning): {Truly Allâh has given you victory on many battle fields, and on the Day of Hunayn (battle) when you rejoiced at your great number but it availed you naught and the earth, vast as it is, was straitened for you, then you turned back in flight.}[9: 25].
The most important act Allah demands from Mujahideen is to supplicate Him as much as possible. Allah Says (interpretation of meaning): {O you who believe! When you meet (an enemy) force, take a firm stand against them and remember the Name of Allâh much (both with tongue and mind), so that you may be successful.}[8: 45].
But when a given group opts for arguing and using reason and logic in everything even in things that do not match the nature and characteristics of the mind prioritizing the latter over Sharia texts, it (this group) looses its ability to weigh things properly hence denying evident Sharia matters like the torment of the grave.
In addition neglecting the obligation of enjoining virtues and forbidding evil is a major sin. On the other hand, following the deviant groups such as Muatazilah and others is a disaster which is unsuitable for Muslims who follow the Prophet's and his companion's way.
4. We advise our brother to be neutral, not to be partial for a person or a group. His aim should be to follow the truth regardless of where he finds it.

May Allah Guide all of us to the right path.

Allah knows best.