The New Testament teaches that Christ was baptized to “fulfill all righteousness” (Matthew 3:14–15)--what does this mean?

Baptism meant one thing, and one thing only, to Jesus: his death at Calvary. When James and John asked to sit at Jesus' left hand and right hand when He came into His glory, Jesus said,

"'You don't know what you are asking,' Jesus said. 'Can you drink the cup I drink or be baptized with the baptism I am baptized with?'" (Mark 10:38 NIV)

When we as Christian believers are baptized, we bear public witness to our death TO sin. When Jesus was baptized, He bore witness to the hosts of both heaven and hell that His death was FOR sin (see Romans 6:1-3; 1 Peter 3:18; 2 Corinthians 5:21).

The righteousness of which Jesus spoke at His baptism by John has at least two aspects:

1. The righteousness He fulfilled by giving His life as a ransom for sin (Matthew 20:28; Mark 10:45). His obedience unto death, even death on a cross, was the ultimate fulfillment and crowning glory of His life on earth (Philippians 2:8 NIV).

2. The righteousness He provided to those who would one day be IN Christ through the giving of His life as a ransom for sin (2 Corinthians 5:21). In the eternal counsels of God's will and plan for the ages, Christ as the Lamb of God had already been slain:

"And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain from the foundation of the world" (Revelation 13:8).

In short, Jesus, unlike us, never had to die TO sin in His own life. He alone was the perfect, spotless, sinless Lamb of God, of whom it was said,

[He] did no sin, neither was guile found in his mouth (Peter 2:22 KJV)

Jesus was the only person who ever lived who could rightly ask his accusers,

"Which of you convinceth me of sin?" (John 8:46 KJV).

The answer, of course, was "No one." Jesus did not die for His own sins, but FOR the sins of humanity.

"For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit" (1 Peter 3:18 KJV).

We, on the other hand, because of our sin-stained souls are called by God to repent, to be cleansed, and to die TO sin and self.

When we come to Christ by faith, confessing Him as Savior and Lord, He graciously imputes to us His righteousness as a gift, a gift made possible through His atoning work at Calvary. By faith, we become the very righteousness of God through Him (2 Corinthians 5:21). Thereafter, whenever God looks upon us, His children, He sees the righteousness of His beloved Son. To be sure, we cannot get any better than that!

In conclusion, the righteousness Jesus fulfilled at His baptism was symbolic of the righteousness He would fulfill three years later at the cross. By fulfilling completely His Father's will for His life to the point of dying,

"the just [One] for the unjust [ones]" (1 Peter 3:18),

Jesus made His righteousness available to anyone who calls upon the name of the Lord to be saved.

We too often consider the Divinity of Jesus and overlook his humanity.

Jesus was and is a man, certainly he was no ordinary man. As a man his humanity would have the same desire to sin as does any other man.

Jesus baptism was; as is ours, a signification of rejection of that nature in favor of the new Righteousness inherited at salvation. In short Jesus the man was signifying that:

1. the human cannot break the bonds of sin without the intervention by the blood of salvation

2. As a man he was rejecting that sin nature and accepting the grace of God. Put another way Jesus the man was rejecting the World in favor of Heaven.

Remember that Jesus was in the flesh;

John 1:14 KJV

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.

Luke 24:39 KJV

Behold my hands and my feet, that it is I myself: handle me, and see; for a spirit hath not flesh and bones, as ye see me have.

We also need to remember what Jesus said to Peter:

Matthew 26:41 KJV

Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak.

The reason Salvation works is because Jesus was an acceptable Sacrifice. By that what I am alluding to is When God had the nation of Israel choose a sacrificial Lamb; he required that it be perfect, or that is without blemish.

In the case of Jesus he had to be sinless in order to be without blemish. Being without sin means that he never disobeyed the Father, which Jesus did even to the cruel death on the cross; but it goes beyond that in that if he were to be without blemish meant he would have to be the in same state as man was when God breathed the breath of life into him in the beginning:

Genesis 2:7 KJV

And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.

That man had never disobeyed God.

So how did Jesus get back to that state? The answer to that is he did it just the same way you and I do.

(Keep in mind this fact that it is not the knowledge of good and evil which made man unacceptable to God, it was the desire brought on by that knowledge.)

Baptism is the burying of the old sin nature and reverting to the original sinless nature of the man originally created by God in the beginning. This is possible because it was the act of disobedience of Adam and Eve which made them unacceptable to God.

Let's take a look at some Scriptures which may clear this up:

Genesis 2:25 KJV

And they were both naked, the man and his wife, and were not ashamed.

They were not ashamed because they did not have the desires of the flesh. When God came to the garden in the cool of the evening Adam said:

Genesis 3:10 KJV

And he said, I heard thy voice in the garden, and I was afraid, because I was naked; and I hid myself.

God knew immediately that they had sinned, because up until this time they had been naked, but now the nakedness of Eve had caused a desire in Adam, which God knew stemmed from the sin nature.

Genesis 3:11 KJV

And he said, Who told thee that thou wast naked? Hast thou eaten of the tree, whereof I commanded thee that thou shouldest not eat?

And so the human part of Jesus, just as you and I: must reject that sin nature and once again be acceptable to God.

However in our case we have more to do than Jesus did, in that we have acted in that sin nature, and must therefore Repent of that sin, by repent what that entails is to reject that sin nature inherited through the flesh and also to totally regret having disobeyed God in the first place and the important part is to try as hard as we can not to sin again. And when we do sin again, remember these Scriptures:

1st John 1:9 KJV

If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.

Mat 18:21 and 22 KJV

21Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times?

22 Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven.

However we must keep in mind that we must first be truly sorry for our sin, and ask his forgiveness each and every time we sin.

From a Mormon (LDS) perspective:

First of all, Christ was part god and part man, meaning He had control over His life, He could give it but no one could take it. But being part flesh, he was subject to temptations.

James 3:5

Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.

It is clearly stated that unless we are baptized, we cannot enter the Kingdom of Heaven. Christ, a mortal on earth, was subject to the same laws. He was perfect, yes, but unless he was baptized, he could not return to His Father. Baptism is much more than a cleansing of sin. It opens up the gate to the path which leds to eternal life.

Matthew 7:21-23

Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.

Christ was baptized as an example to us, he had to "fulfil all righteousness." A greater explaination and clarification is found here

Jesus' baptism was showing that He was willing to do God's will/plan for His life (death and resurrection). So when it says,

"You don't know what you are asking," Jesus said. "Can you drink the cup I drink or be baptized with the baptism I am baptized with?" (Mark 10:38 NIV)

Jesus is saying God's will is different for everyone. He emphasized this by saying basically the same thing twice. Jesus was destined for the cross. God's basic will for us is to acknowledge His sacrifice for our sins and give Him lordship of our lives, so He can raise us up too when we die.

So when Jesus says "to fulfill all righteousness" as the reason for His baptism, He is saying it is God's will that everyone decides to turn his/her life over to God. That it needs to be a conscious decision. Consequently, a person cannot be saved just because they pray or read self-help books or meditate or become a martyr for a cause or work miracles etc. 1 Corinthians 13 states the same thing in expanded form. The love that resurrected Jesus is only found in acknowledging God's sacrifice for our sins and accepting God/Jesus as Lord.