Trust in God means to rely upon Him and to commend all affairs to Him by diverting from anyone or anything else. The source of trust in God is power of heart and conviction. Likewise, loss of trust in God is originated from feebleness of heart and conviction and influence of apprehensions and illusions:
“Allah is Sufficient for the needs of whoever trusts in Him. (65:3)”
“Allah loves those who trust Him. (3:159)”
“(Muhammad), say, ‘Nothing will happen to us besides what Allah has decreed for us. He is our Guardian. In Allah alone do the believers trust.’ (9:51)”
“If Allah is your helper, no one can defeat you. However, if He abandons you, who would help you? The true believers trust in Allah. (3:160)”
Amir ul-Mu’minin (a) said: “Regarding all of your affairs, seek the refuge of your Lord, for you are seeking the refuge of a sheltering haven and powerful sanctuary.”
“Within his sermons to his son, Luqman said: Son, for him who is unconvinced and ill-intentioned in the matter of seeking earnings, he should learn lessons from the fact that Allah has created him and guaranteed his sustenance in three states; He secured him and gave him his decided shares of sustenance without exerting any efforts or planning for any proposal in gaining them.
First, when he was in mother’s womb, Allah was giving him his sustenance without being exposed to coldness or heat.
Then, Allah caused him to go out to this world and gave him his shares of sustenance, which were sufficient and nutrient, from the mother’s breast while he had no power to earn.
Then, when he was weaned, Allah gave him his share of sustenance out of the earnings of his parents who were very kind to him to the degree that they preferred him to themselves in many situations.
When he attained maturity and went on seeking earnings for himself, he became unable to stand it, mistrusted his Lord, denied the rights that he should defray from his earnings, and behaved stingily with his dependants and himself. All that was because of his expecting scarcity, mistrusting Allah and suspecting His promised recompense in this world and the world to come. See, my son, how evil such man is!”
Imam as-Sadiq (a) said: “Richness and honor are wandering. They settle only when they find a situation of trust in Allah.”
He (a) also narrated that Allah revealed to Prophet David (a): “For any one of My servants who relies upon Me heartily exclusively, then the heavens and the earth plot against him, I will surely grant him an exit between them to escape their plots. But for the servant who relies upon any of My creatures, I will cut the rope that links him to the heavens and will sink the earth under his feet and, then, I will not care where he will perish.”
“He who is given three things will not be deprived of three others: he who is granted supplication to Allah will not be deprived of response; he who is granted thankfulness will not be deprived of increase; he who is granted trust in Allah will not be deprived of His security.”
Read in the Book of Allah: ‘Allah is Sufficient for the needs of whoever trusts in Him. (65:3)’
‘If you give thanks, I shall give you greater (favors) (14:7).’
‘Pray to Me for I shall answer you prayers. (40:60).’”