Why He called God=s only Begotten- Son, since we are also God's children?

Because Christ alone is God's own eternal Son, whereas we are accepted for His sake as children of God by grace.

Why do you call Him our Lord?

Because, not with gold or silver but at the cost of His blood, He has redeemed us body and soul from sin and all the dominion of the devil, and has bought us for His very own.

I. Christ Is God's Son

A. John used Trinitarian phrases to describe creation and providence. In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by him; and without him was not any thing made that was made. (John 1:1-3)

The divinity of Christ is distinct and His relationship to both
God and to humanity is different from our relationship.

 B. John expanded his introduction to say that the Savior we encountered in Jesus Christ is the same Word of God identified in the Trinity. And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth. (John 1:14)

Christ is eternally begotten and we are adopted and then born into time.

C. This unique representative of God, the Son of the Father, is the only clear and entirely reliable source we have for information about God. No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him. (John1:18)

Son represents an eternal relationship.

D. The Son of God is the summary and perfection of God's revelation. God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds; Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high; (Hebrews 1:1-3)

In Jesus we finally learn what the gospel message in Israel and the Church were all about and what God has in mind for believers - all the symbols come into focus.

E. Our sonship as believers is by adoption and not by the unique begetting. Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will, To the praise of the glory of his grace, wherein he hath made us accepted in the beloved. (Ephesians 1:5-6)

He is the natural Son of God and we are adopted children by grace.

F. The believer's sonship comes through the grace of God alone. But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: (John 1:12)

Our sonship is a gift; rather than an expression of nature.

II. Believers Affirm Our Sonship Through Jesus= Sonship

A. Because Jesus is the uniquely begotten Son of God, it is possible for Him to redeem an adopted family for God. Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers; But with the precious blood of Christ, as of a lamb without blemish and without spot :(I Peter 1: 18-19)

Because Jesus is God's uniquely begotten Son, I can be God's adopted son.

B. All the good things believers obtain in the gospel come through Jesus. But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light :Which in time past were not a people, but are now the people of God: which had not obtained mercy, but now have obtained mercy. (I Peter 2:9-10)

Adoption is a difficult business and it changes relationships without changing the core genetic make-up in itself - adoption won't make brown eyes blue.

Ill. Acknowledge That Jesus is Your Lord

A. Always remember the price paid for redemption and adoption. Ye are bought with a price; be not ye the servants of men. (I Corinthians 7:23)

We now have something to which we had no inherent right.