Praise be to Allah, and peace and blessings be upon the Messenger of Allah. To proceed:
When a person says: “I entrust my religion, my trust, and the final outcome of my deeds to Allah,” or entrusts his money, family, or something similar to Him, this is in reality a supplication to Allah, Exalted is He, asking Him to protect what has been entrusted to Him.
Supplication is an act of worship and one of the means by which a desired matter may be attained and harm may be prevented. However, Allah, Exalted is He, has not guaranteed that He will answer a supplication in the exact way the servant wants and at the time he wants. He may hasten the fulfillment of the supplication for him, or reserve something better for him in the Hereafter, or avert from him an equivalent amount of harm.
Therefore, if a person entrusts something to Allah and it is then stolen, this does not mean that entrusting it to Allah was of no benefit or that Allah did not hear his supplication. Rather, Allah may have decreed something else for a wisdom known to Him. The servant still receives the reward for supplicating and turning to Allah.
The Prophet ﷺ said: “There is no Muslim who makes a supplication that contains neither sin nor severing family ties except that Allah grants him one of three things...”: either He hastens his supplication for him, or stores it up for him in the Hereafter, or averts from him an equivalent amount of harm.
Therefore, a servant should not despair or object when he does not see the effect of his supplication in the way he wanted. Rather, he should think well of Allah, continue supplicating, and not be hasty in expecting an answer.
In conclusion: Entrusting one's money or anything else to Allah is a legislated supplication, and the theft of something after entrusting it to Allah does not mean that the supplication failed or that Allah did not protect His servant. The answer may have taken another form known to Allah, Exalted is He.
And Allah knows best.