When I read this verse, a uestion came to mind:
"How did Abraham serve God?"
I mean, really, what did Abraham do for God that showed him to be a servant?
God invited Abraham to leave country, kith, and kin to a new land that He would give to Him:
"Now the LORD had said unto Abram, Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee:'
"2And I will make of thee a great nation, and I will bless thee, and make thy name great; and thou shalt be a blessing:
"3And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed." (Genesis 12: 1-3)
What was Abraham supposed to do? Trust God and go.
And he did not trust God perfectly, because he took his nephew Lot with him, even though he was to completely go away from his family--all of them (Lech Lecha).
So, again--how did Abraham serve God exactly?
Abraham believed Him!
"And he believed in the LORD; and he counted it to him for righteousness." (Genesis 15:6)
How does God want us to live, anyway?
"Behold, his soul which is lifted up is not upright in him: but the just shall live by his faith." (Habakkuk 2:4)
We live by faith, the faith of the Son of God!
"I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me." (Galatians 2:20)
So, How do we serve God today?
We believe on Him--just as He served God by believing Him:
"Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent." (John 6:29)
We are all children of Abraham:
"And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise." (Romans 3:29)
"Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all," (Romans 4:16)
That's what service to God comes to for us. What really can we do for Him of ourselves! We are called to believe on Him. and His life flows through us to do good works.
Just as Abraham trusted God to bless Him, to keep Him, and to ensure glory and honor for him and his descendants, which includes you and me!