Beloved Son, et al.

[Hanseng]

There are 4 expressions in the NT that describe Jesus: Beloved son, Son of God, firstborn, only begotten. Son of man is another that won't be discussed now.

1)"Beloved Son" appears 9 times in the NT. It is used primarily at the baptism and transfiguration of Christ. It is also used in the parable of the vineyard (Lk. 20:13). Paul refers to Timothy as his beloved son (1 Co. 4:17, 2 Tim. 1:2) 2 Peter 2:17 refers to Christ receiving honor and glory when he was called the beloved Son on the mount of transfiguration.

2)"Son of God" appears nearly 100 times in the NT This expression is used when others are confessing the identity of Christ (Mt. 27:54), when demons are addressing Christ (Mt. 8:29). Satan used it when testing Jesus in the wilderness (Mt. 4:3) et al.

Jesus was accused of blasphemy for identifying himself as the Son of God (John 10:36). The Jews wanted to kill Him for this (John 19: 7).

3)"Firstborn" 9 times in the NT: the firstborn among many brethren (Rom. 8:29); the firstborn of every creature: (Col. 1:15); the firstborn from the dead (Col.1 :18, Rev. 1:5); when he bringeth in the first begotten into the world, (Heb. 1:6); church of the firstborn (Heb. 12:23) [Not sure if the firstborn is referring to Christ or the church members].

4)"Only begotten" appears less than 10 times. 4 of those appearances refer to the only child of a parent (Lk.7:12, 8:42, 9:38, Heb. 11:17). Hebrews 11:17 refers to Isaac who was the child of promise but not Abraham's only son. John 1: 14, 18; 3:16, 18, and 1 John 4:9 refer to Christ as the only begotten Son of God.

[Hanseng]

"Firstborn" is a term which usually the describes the son who was born first. In some cases that is not true. Jacob and Esau, for example. Even though Esau was the son born first, the privilege of inheritance, which normally goes to the first born, went to Jacob instead (Gen ch 25,27). Reuben is another example. 

Even though Reuben was the son born first the right of inheritance was taken from him and given to the son of Joseph.  Reuben lost his place because of sin (1Ch 5:1).

The language describing Reuben as the firstborn is similar to the NT description of Christ: "

Ge 49:3 Reuben, thou [art] my firstborn, my might, and the beginning of my strength, the excellency of dignity, and the excellency of power:

Col 1: 17 And he is before all things, and by him all things consist.
18 And he is the head of the body, the church: who is the beginning, the firstborn from the dead; that in all [things] he might have the preeminence.

Reuben lost his status as the firstborn due to his frolic with one of his father's concubines )1Ch 5:1).  Joseph had 2 sons, Manasseh, the firstborn and Ephraim. The birthright was arbitrarily assigned to Ephraim by Jacob (Gen 48:17-19).

Three examples of the status of firstborn being assigned to the son who was not born first.

[Hanseng]

Firstborn was a status that had to be maintained.  The example of Reuben is a clear illustration of that in the OT. Reuben sinned and forfeited his status as firstborn (1 Ch. 5:1). Er, Judah's firstborn was killed by the Lord for his wickedness (Gen. 38:7). Both Jesus and John the Baptist are referred to as firstborn sons with regard to their actual nativity (Mt 1:25; Lk 2:7). Jesus is called the firstborn of the dead after his resurrection (Col 1:18). The KJV of Revelation 1:5 refers to Christ as the first begotten of the dead. The same Greek word is used in Colossians 1:18 as in Revelation 1:5. Jesus is the first born/begotten of the dead. Jesus was not actually the first person to be resurrected. The daughter of Jairus, The widow of Nain's son and others were brought back from the dead before Jesus was. Christ's position as firstborn of the dead, was a status that he held. The firstborn of Pharaoh shared the throne with his father (Ex 11:5; 12:29).

If Jesus had sinned, which was a real possibility, considering that he had his own will that could conflict with his Father's will, he would have not held the status as firstborn. Like Reuben and Er, the son of Judah, his wickednesss would have deprived Jesus of that status. With the status of firstborn came the right of inheritance. That would have also been lost.  The prodigal son's older brother, as the firstborn, had a right to everything his Father possessed (Lk 15:31).