Apart from Allah no one is the Lord

When a believer has developed a firm and complete conviction that apart from Allah no one is the Lord of the creation and none is the cause of all the causes except Him, He does not repose hope in anyone except Allah. Hazrat Ali (a.s.) states: 
"You must not rely upon anyone except the Lord." 
(Nahjul Balagha).

As we have mentioned before, the origin of everything is Allah and the centre of all creation is He alone. In the same way every goodness of man for his fellowbeings also originates from Allah. As it is mentioned in the Holy Quran, 
"Good actions are only from His (Allah's) hands."

At the end of Surah Yunus Allah says, 
"And if Allah should afflict you with harm, then there is none to remove it but He, and if He intends good to you there is none to repel His grace; He brings it to whom He pleases of His servants; and He is the Forgiving, the Merciful." 
(Surah Yunus 10:107)

At another place the Quran says, "And whatever favour is (bestowed) on you, it is from Allah..." 
(Surah Nahl 16:53)

Thus, it is clear from the above discussion that all that is present in the material and the ethereal spheres is subservient to Allah.

"There is no one in the heavens and the earth but will come to the Beneficient God as a servant." 
(Surah Maryam 19:93)

If someone reposes hope in anyone except Allah his hopes are extinguished so that he can realise his true master, i.e. Allah.

"I will severe the ties of hope of those who repose hope in others."

Thankfulness to the Provider of Bounties

The master of the Universe is Allah and He bestows all the bounties, hence He must be thanked for these. Because all the good deeds are only through His hands. He gives whatever goodness He likes to anyone of His choice. That is why we say with a firm belief, "Al-hamdo lillah" (The praise is only for Allah).

Thankfulness for Capability (or Means) is also Necessary

If we are receiving sustenance or help from some means, we must be thankful for these too. However we should not consider these means or intermediaries to be independent of Allah. We must accept them only as the agents through whom Allah is causing His Mercy to reach us. These agents only act as a medium of passing the bounties of Allah and hence they must also be acknowledged; as ordered by the Masoom (a.s.).

"One who does not thank his apparent giver (the agent or the means), it is as if he has not thanked his real giver (Allah)." 
(Behaarul Anwaar)

"The most thankful amongst you towards Allah is the one who is most thankful to the people (who have helped you)." 
(Safinatul Behaar)

There is no doubt that if one considers his helper to be the original doer of good (independent from Allah), he has surely committed shirk.

Hidden Shirk in the Praise of the Creature

"And most of them do not believe in Allah without associating others (with Him)." 
(Surah Yusuf 12:106)

While explaining this verse, Imam Ja'far as-Sadiq (a.s.) informed that one form of shirk is, 
"Like the saying of someone that if so and so had not been there I would have been destroyed. If so and so had not been there I would have got that thing. In the same way is to say that if so and so had not been there my children would haveperished." 
(Behaarul Anwaar)

Such utterances signify the type of belief the speaker possesses. If he really has such a belief then he is surely a polytheists (mushrik). After this Imam (a.s.) said, 
"If one says, 'If Allah had not helped me through such and such person I would have perished,' there is no harm in it." In fact this is the essence of Tawheed.

Hazrat Imam Ja'far as-Sadiq (a.s.) and the Thankful Beggar

Masma bin Abdul Malik relates that Imam Ja'far as-Sadiq (a.s.) was at Mina (in Makkah) when a beggar approached him. Imam (a.s.) ordered that a bunch of grapes be given to him. The beggar said, "I do not need these, if possible give me money." Imam (a.s.) did not give him anything but said, "May Allah make you self-sufficient." After this another beggarapproached. Imam (a.s.) picked up three grapes from the bunch and offered them to him. The beggar picked them up and said, "All Praise is for Allah (only) who has given me sustenance." Imam (a.s.) said, "Wait", and he placed as many grapes as his hands could hold. Twice again he gave him the same quantity. The beggar thanked Allah again. Imam (a.s.) again stopped him and asked his slave how much money he had. The slave replied, "Twenty dirhams." Imam (a.s.) ordered him to give these to the beggar. The beggar took the money and said, "All praise is for Allah alone. O Allah You are the sustainer, You are One, there is no partner for You. Imam (a.s.) again stopped him. Then the Imam (a.s.) removed his shirt and gave it to the beggar and said, "Wear it." The beggar put the shirt on and thanked Allah who had bestowed him with the dress and made him happy. At this stage the beggar turned towards Imam (a.s.) and said, "O slave of Allah may Allah reward you for this." After this he went his way. The narrator says that if the beggar had not addressed the Imam (a.s.) as such, Imam (a.s.) would have continued to give him gifts for his thankfulness to Allah. 
(Al Kafi)

Tawheed and Tawakkul (Reliance)

It must be remembered that all the causes are in the hands of the One who is the final cause. Those who believe in the Oneness of Allah should rely only upon the Almighty Allah for all their affairs. They must realise that all the effects owe their cause to Allah. Even if all the venues for his success are open he will not achieve success if Allah's will is contrary to it. On the other hand if all the ways of success are closed he will definitely succeed if Allah wills. Even if all the means of causing him injury come together no harm shall come if Allah intends to protect him.

Tawheed and Acceptance (Taslim)

One who believes in Tawheed should accept all the Divine decrees with humility. He should believe that various factors like honour and dishonour, health and ailments, richness and poverty, death and life are all according to the Divine decree. He should not oppose any of these either by speech or by actions. He should not even express his opinion in such affairs. For example, "Why has this happened? It should have been like this." Or to say, "Why did it not rain? Why is it so hot?" One should not say, "Why has Allah not given me wealth or children?" "Why did such and such person die in his youth and why did the other attained old age?" "Why has Allah prohibited this and made obligatory that?"

One who utters such things makes himself a partner in the absolute authority of the Almighty Allah.

There maybe people who worship the One and only God, establish prayers, pay the Zakat, perform Hajj and also fast during the month of Ramazan. But if they have any objection against those obligations prescribed by Allah or His Prophet (s.a.w.s.) and say, "Why was it not this way?" or even if they have such thoughts and do not express them in words, still they are polytheists (mushrikoon).

"But no! by your Lord! they do not believe until they make you a judge of that which has become a matter of disagreement among them, and then do not find any straitness in their hearts as to what you have decided and submit with entire submission." 
(Surah Nisa 4:65)

Allama Majlisi comments, "...any objection against the Divine decree and the utterances of the Pure Imams (a.s.) is tantamount to Shirk."

Thus it is obligatory for the believers of Tawheed that when they fall into misfortune and calamities they should restrain their tongues and hearts from objecting against the Divine decree. However the weeping and expression of grief at the death of friends and relative is allowed and rather recommended. What is not permitted is to say, "Why has this happened? It should not have happened."

Tawheed and Love

The worshippers of the unique God should accept that Allah is the provider of him and all the existing things. Whatever he gets is due to the beneficence of the Almighty. The apparent causes and the effects are also in control of Allah. Then it is Him only who deserves unlimited love and attachment. If someone else deserves to be loved it is only due to his being the beloved of Allah. This is because such a love is itself commanded by Allah. Divine personalities like the Holy Prophets (a.s.), Imams (a.s.), the angels and the true believers are those whose love is commanded by Allah.

In the same way, to show attachment to the gifts of Allah is allowed if such an attachment would exhibit our thankfulness for the bounties. To love our family, possessions and the worldly life is also worship in this way. However, to love all such things without considering the divine aspect renders one to be a mushrik (polytheist). If one loves something more than he loves Allah, then it is a kind of shirk. If he prefers something above the love of Allah it is totally Haraam. Consequently he becomes liable for punishment. For example if someone loves monetary wealth more than Allah then it would be difficult for him to fulfill the religious obligation of Zakat etc. Various ayats of the Quran and traditions mention this fact.