In order to trust in God, one must first believe that He is able to provide us with what we need and want. Nevertheless, trust in God is not always the result of having faith, since a person who has faith may still be afraid that he has sinned and that he is therefore unworthy of God’s kindness.

Faith in God comes before trust in God:

With regard to faith and trust, one of them requires the other, whereas the opposite is not true. Faith precedes trust, although it does not [inevitably come] with trust, and does not need it in order to exist. On the other hand, the presence of trust indicates the presence of faith; trust cannot precede it or exist without it. Faith is like the tree and trust is like the fruit; one can trust in another only if he believes that the other is capable of fulfilling his requests.

The believer may fear that he is unworthy:

Not every believer has trust in God, because one may be afraid that he has sinned or that he has already received the reward for his good deeds, through miracles that the Creator has performed for him. When he finds himself sinning against the Creator, he does not dare to trust that He will save him or give him his heart’s desire. Rather, he endeavors to escape from his troubles and to attain his desires using worldly means…Someone who believes in God may be afraid of the consequences of having sinned, but one who has trust in God is not afraid of the consequences of having sinned. (Ramban, HaEmuna VehaBitaĥon 1)

If a person works and endeavors to sustain himself, this does not mean that he does not have complete trust in God. Taking action is necessary because, after the sin of Adam, God decreed that man would have to put in effort in order to eat. Effort is not the source of our success, but it is impossible to succeed without it. Once effort has been made, there is room for God’s blessing, and one no longer needs to over-exert himself. Likewise, avoiding danger does not contradict trust in God, as God wants human beings to keep themselves safe.

One must put in effort to make a living, because this is what God has decreed:

The way to safeguard a person from these troubles is through trust, by casting his burden entirely upon God. One should know that it is impossible that what has been allotted to a person can be diminished in any way, and as our Sages said, “A person’s entire livelihood is allocated to him from Rosh HaShana” (Beitza 16a). One could remain idle and this decree still would be fulfilled, were it not for the punishment that all mankind previously [received, at the sin of the tree of knowledge]: “By the sweat of your brow shall you eat bread” (Genesis 3:19). Consequently, one is obligated to put in some degree of effort for the sake of his livelihood, as this is what the heavenly King decreed; it is like paying a tax…But it is not that the effort is effective; rather, it is necessary. Once a person has made an effort, he has fulfilled his obligation; there is now room for the blessing of Heaven to rest upon him, and he does not need to spend his days continuing to over-exert himself.

God wants people to look after themselves:

God created human beings with sound intellect and good judgment so that they will follow the right path and guard themselves from harmful elements that were created to punish the wicked. When one does not act wisely and puts himself in danger, this is not trust, but foolishness. Such a person has sinned, as he has gone against the will of the Creator, who wants people to look after themselves. (Rabbi Moshe Ĥayyim Luzzatto, Mesilat Yesharim 21, 9)