This was accomplished not only by the Son but also with the Father (John 8:16, 29) and through the Spirit (Luke 1:35; Matt. 1:18, 20); hence, He was called the mighty God and the eternal Father (Isa. 9:6), but He was lying in a manger as a human baby (Luke 2:7).
The God-incarnated Jesus lived on the earth as a man for thirty-three and a half years.
He passed through human living to experience all the trials and troubles in human living (Heb. 4:15).
He manifested God's attributes (1 Tim. 3:16) in His human virtues in the flesh. His human virtues were the expression of the divine attributes.
The incarnated God went through temptations, yet without sin, and He had no sin even though He was made sin (Heb. 4:15; 2 Cor. 5:21).
Hebrews 2:10 says that Christ was made perfect through sufferings.
Thus, He has qualified Himself to be the Redeemer and Savior of the men of sin. He has been tested and approved. He "graduated" from human living. That gave Him the qualification to be our Savior.