Mama Lushen: 1

It is well known that Rebbe Nachman encouraged people to engage in personal prayer in their native language. In those places where people spoke Yiddish, he encouraged them to pray in Yiddish. He explained that when people pray in the language in which they are most comfortable, the heart is connected to his words and he can better connect to Hashem.

Elsewhere he explained that by speaking in his native Yiddish a person will find himself more inspired.

One Source: 5

This concept also sheds some light on our relationship with Hashem. In davening a person should be attempting to focus fully on Hashem; to feel that he is the vessel to receive the light from Hashem. He wants to get to the point where he feels that he must have this connection and would not exchange it for anything that would diminish his relationship with Hashem.
This alluded to in Rebbe Nachman's story of the Smart Man and the Simple Man. The Smart Man, with all of his genius, kept changing from profession to profession and never discovered who he truly was and where he belonged. He ended up with nothing. The Simple Man stuck to one profession, poor as he was at it, and in the end it led him to greatness.

The Value of a Relationship: 2

When two people are involved in a close relationship each one sees the good points of the other, and not what they lack. As the Rebbe R' Elimielch taught to pray "That I should not see anything demeaning and I will despise him." You don't want to see the dark parts of the other person and end up distancing yourself from her. So, too, when Hashem is in relationship with a person He chooses not to look at the repulsive parts of the person. As the Pasuk says: לא הביט און ביעקב ולא ראה עמל בישראל ה' אלוקיו עמו ותרועת מלך בו, "He does not see out the iniquity in Yaakov and does not see the wrongdoing in Israel. Hashem his God is with him and the love of his king is in him."

There are those who err and spent their time communicating with Hashem telling Him of all of their sins and asking Him to have mercy on them, rather than engaging in a real heart-to-heart conversation. (The time for self-reckoning is not then.) It is like a child whose parent is feeling very proud of him, and the child stands up and announces all of the reasons why the father should be disappointed in him. He ruins the moment.

On the other hand if he correctly takes advantage of the opportunity by connecting joyfully with his inner self to Hashem, without looking at any of his shortcomings, it will soften the heart of Hashem and the person will come to real deep regret that will bring him to truly turn to do better. Otherwise, if he only focuses on his faults, he can come to depression and fall even further. A broken heart is one that is softened towards Hashem (a heart of flesh), not one that is depressed (a heart of stone). A broken heart should leave one desirous of Hashem, happy and given over to Hashem. As Rebbe Nachman writes: When a person is constantly happy he can easily devote some time each day to soften his heart before Hashem and to speak what is in his heart to Hashem. But when he is depressed it is difficult for him to connect and to speak his feelings.