Hakadosh Baruch Hu set us up in a way that demands that we seek him out and beseech him for that which we need. Even though Hashem knows and understands the needs of each and every individual (and similarly ‘hears the words of our hearts’), he suppresses his knowledge (in a manner of speaking) so as to maintain his ‘derech hatevah’ which demands that we reach out to him in supplication and prayer for that which we are lacking.
Hashem does this for our sake, so as to provide us with the incredible opportunity for growth and closeness to him, which is derived directly from our Tefilos.
Therefore, we should not think that we don’t need to daven, since Hashem understands exactly what we need anyway… This is a big mistake and we need to be aware of the fallacy in thinking this way. Hashem purposefully stifles his awareness of our problems, because he wants us to specifically call out to him in our time of distress and THEN he will shower us with all manners of salvation.
An analogy to explain this, is that of a person who becomes deathly ill with a sickness that his father, who is a world famous physician – specializes in. Can it be argued that the Father should come immediately to heal his sick child…if he is completely unawres of the problem?!
Hakadosh Baruch Hu “waits” for us to inform him of and describe to him our problems, so that he can bring us Yeshuos!
Hashem needs to hear from us before we can hear from him!
<Heard From Rav Shimshon Pincus>