Ellen G. White said that Christ received all things from His Father including His life which Christ in turn can give to us. “For as the Father has life in himself; so has he given to the Son to have life in himself.” John 5:26.
“All things Christ received from God, but He took to give. So in the heavenly courts, in His ministry for all created beings: through the beloved Son, the Father's life flows out to all; through the Son it returns, in praise and joyous service, a tide of love, to the great Source of all. And thus through Christ the circuit of beneficence is complete, representing the character of the great Giver, the law of life.” — (Ellen G. White, Desire Of Ages, 21.2)
The Father gave not only His life to His Son but His Spirit also and why they are one in Spirit. The Father and Son were “two in individuality, yet one in spirit.” — (Ellen G. White, Youth's Instructor, December 16, 1897)
“He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?” The Father gave his Spirit without measure to his Son, and we also may partake of its fulness. Jesus says: “If ye then, being evil, know how to give good gifts unto your children: how much more shall your Heavenly Father give the Holy Spirit to them that ask him?” — (Ellen G. White, Review and Herald, November 5, 1908)
“God has sent his Son to communicate his own life to humanity. Christ declares, “I live by the Father,” my life and his being one. “No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him,” “For as the Father hath life in himself; so hath he given to the Son to have life in himself; and hath given him authority to execute judgment also, because he is the Son of Man.” The head of every man is Christ, as the head of Christ is God. “And ye are Christ's, and Christ is God's.” — (Ellen G. White, Home Missionary, June 1, 1897)
Ellen White says that the life of God and the life of Christ is one life, meaning they share the same divine life. It was the life of the Father that was in Christ. His life was also the life of the Father and not something that Christ had independent and separate of the Father. This explains the following quote that Froom abused and used to convert the Adventist Church to the Trinity doctrine. How easy is it to abuse the writings of Ellen White if you do not study all things she wrote on a specific point?
“Jesus declared, “I am the resurrection, and the life.” In Christ is life, original, unborrowed, underived. “He that hath the Son hath life.” The divinity of Christ is the believer's assurance of eternal life.” — (Ellen G. White, The Desire of Ages, p. 530) — Evangelism 616.2
In a later quote she gave more clarity.
“I lay it down of myself” (John 10: 18), He said. In Him was life, original, unborrowed, underived. This life is not inherent in man. He can possess it only through Christ. He cannot earn it; it is given him as a free gift if he will believe in Christ as His personal Saviour.” — (Ellen G. White, Signs of the Times, April 8, 1897)
And consistent with the previous quotes, did you notice that this original, unborrowed and underived life can also be given to man? The life of Christ was original, unborrowed and underived as it was given to Him by His Father. This life can now in turn be given to us through Christ. As the first quote stated, “All things Christ received from God, but He took to give.” And since the life of the Father has been given to His Son, then that means Christ is also self-existent.