According to the quotes from the provided materials, true friendship with the Creator requires that a person's entire life becomes a sacrifice to Him.

The Art of Sacred Sacrifice

According to the quotes from the provided materials, true friendship with the Creator requires that a person's entire life becomes a sacrifice to Him. This does not imply a single act but a constant, selfless pursuit, where every deed, every minor sacrifice, is a sign of readiness to give oneself and everything one has for the sake of God.

In one source it is stated:
"We must strive to arrange our lives so that they all represent a sacrifice to God. When a person is baptized, his hair is cut in the shape of a cross on his head as a sign of his first sacrifice to God. Here the person stands with nothing but the cross and a shirt that barely covers his nakedness; and the first thing he does is to offer God what he can give at that very moment. With this sacrifice begins his spiritual life, his relationship with God, which is a constant offering. And only by continually sacrificing can one become a child of God, only in this way can one attain adoption. To become a son from a slave, one must accustom oneself to sacrifice."
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Another fragment explains that it is through sacrifice that a person attains a sublime nobility akin to that shown by the Lord Himself: "How then can one become a child of God from a slave, from a servant?

It is connected with sacrifice. Nobility in general is connected with sacrifice, and we call an act noble only when a person sacrifices something of his own or even himself for another. The highest act of nobility was performed by the Lord Himself, who gave up His own Son to be killed so that from us—sinful, worthless, foolish people—a family could be created, so that we would be called His children. Which of us, to become kin with a neighbor, would throw his son or daughter out of a window? Such an act would be foolish. Yet the Lord performs this 'foolishness': He hands over His own Son to be torn apart in order to adopt us. And the Son of God comes down to earth voluntarily; He willingly becomes a sacrifice for us."
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From these statements it is clear that establishing true friendship with the Creator requires an immense willingness to sacrifice oneself—renouncing selfishness and striving for a life entirely dedicated to God. It is not so much about material sacrifices (like candles, notes, or money) as it is about a continual self-denial, a living commitment to eternal values expressed by giving everything one can offer at any given moment.

Supporting citation(s):
"We must strive to arrange our lives so that they all represent a sacrifice to God. When a person is baptized, his hair is cut in the shape of a cross... and the first thing he does is to offer God what he can give at that very moment. With this sacrifice begins his spiritual life..." (source: link txt)

"How then can one become a child of God from a slave, from a servant? It is connected with sacrifice. Nobility in general is connected with sacrifice, and we call an act noble only when a person sacrifices something of his own or even himself for another. The highest act of nobility was performed by the Lord Himself, who gave up His own Son to be killed..." (source: link txt)