“No man taketh it from me, but I lay it down of myself. I have power to lay it down, and I have power to take it again. This commandment have I received of my Father”.
The thing to know is that God the Father, His Son and the Holy Spirit have a relationship that is not like anything man experiences. Their relationship exist without sin, it is absent of jealously or any human emotion that would get in the way of their service and purpose.
Jesus did not have to lay down His life, He chose to. Jesus, before He came as a man, was an eternal deity able to take the form of man, He had a measure of omniscience that allowed Him to traverse time and space.
In the account in Psalms, Jesus ask the Father to become the Christ for men in order to save all of mankind. He did not have to do it, He wanted to please the Father because God loves mankind.
7 "I will declare the decree: the Lord hath said unto me, Thou art my Son; this day have I begotten thee.
8 Ask of me, and I shall give thee the heathen for thine inheritance, and the uttermost parts of the earth for thy possession.
9 Thou shalt break them with a rod of iron; thou shalt dash them in pieces like a potter's vessel.
10 Be wise now therefore, O ye kings: be instructed, ye judges of the earth.
11 Serve the Lord with fear, and rejoice with trembling.
12 Kiss the Son, lest he be angry, and ye perish from the way, when his wrath is kindled but a little. Blessed are all they that put their trust in him".
Jesus tells the Sanhedrin that He existed before the time of Abraham, which makes the point of His Deity.
4 "I have glorified thee on the earth: I have finished the work which thou gavest me to do.
5 And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was".
54 "Jesus answered, If I honour myself, my honour is nothing: it is my Father that honoureth me; of whom ye say, that he is your God:
55 Yet ye have not known him; but I know him: and if I should say, I know him not, I shall be a liar like unto you: but I know him, and keep his saying.
56 Your father Abraham rejoiced to see my day: and he saw it, and was glad.
57 Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham?
58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am".
Jesus relationship with the Father is absolute, there is no possibility that God could stop loving Jesus or vice versa, that is a distinction for mankind, alone. Jesus always did that which pleased the Father because of their love for one another.
Man can scarcely relate to such a relationship because of our sin nature that would inevitably get in the way.
28 "Then said Jesus unto them, When ye have lifted up the Son of man, then shall ye know that I am he, and that I do nothing of myself; but as my Father hath taught me, I speak these things.
29 And he that sent me is with me: the Father hath not left me alone; for I do always those things that please him.
30 As he spake these words, many believed on him".