A scientific theory is a unifying concept that explains a large body of data. It is a hypothesis that has withstood the test of time and the challenge of opposing views. The Big Bang Theory and the Theory of Evolution are supported by extensive empirical data. There is no reliable data supporting the some-god-did-it hypothesis, and especially not the Yahweh-did-it hypothesis.
There's no reliable evidence for God/Yahweh, Jesus, Allah, Zeus, Baal, Odin, Quetzalcoatl, Vishnu, Thor, Shiva, or any of the thousands of other gods that people have worshiped. There's also extensive evidence that they are all just myths, created to help soothe our fear of death, and perpetuated through religion to subjugate the underclass into obedience.
Science has shown that there's no need for gods to explain the traditional reasons for a god -- origin of the universe, origin of life, origin of species, origin of humans, origin of morality. Science also shows us the psychological reasons that people believe in god(s). See the 1st link for the video, "Andy Thomson: Why We Believe in Gods" or buy his book at the 2nd link. Also, check out Michael Shermer's "The Believing Brain" at the third link, and his "Why People Believe Invisible Agents Control the World" at the 4th link.
Yahweh is typically defined as all-knowing, all-powerful, all-loving, and having free will. Such a god is internally and externally incongruent, and thus cannot logically exist. An all-powerful and all-knowing god with free will can't exist, because it could not both know the future and change it. An all-powerful and all-loving god can't exist and allow the true horrors that occur to sentient beings.
All reliable evidence points to Jesus Christ being just a myth. There is no reliable evidence that Jesus even existed, and significant evidence that he didn't. The evidence is in the Bible, the other religions of the time, the lack of writings about Jesus by historians of the 1st century, and the lack of writings about Jesus by anyone until a decade or more after his supposed life.
The story of Jesus can be shown to be just a myth created to fulfill prophesy, cobbled together out of stories from the Old Testament and previous gods and myths -- created in the 40's and 50's by Paul of Tarsus (who exhibited symptoms of epilepsy and had delusions of Christ talking to him), the other apostles, the unknown authors of the gospels in the 70's or later, and many other people. The reliable evidence for this is overwhelming.
Paul and the other epistle writers don't know any biographical details of Jesus' life, or even the time of his earthly existence. They don't refer to Bethlehem, Nazareth, Galilee, Calvary or Golgotha — or any pilgrimages to what should have been holy sites of Jesus' life. They also don't mention any miracles that Jesus was supposed to have worked, his virgin birth, his trial, the empty tomb, or his moral teachings. To them Jesus was largely a sky-god, who existed in the spiritual past.
If Jesus had actually existed, Paul would have written about his life, disciples, teachings and miracles. Paul did not write about any of this. Paul even wrote (1 Cor. 1:22-23) that Jesus did no miracles. Also, Paul thought that Peter was another (competing) epistle writer. Paul referred to James as the Lord's brother, not Jesus' brother. This is much like people of a religion who refer to each other as brothers. Paul wrote (in Romans 16:25-26, Galatians 1:11,12) that he knew Jesus through revelation, which is another term for fantasy and delusions. We can also tell that people were accusing Paul of lying, because he attempted to defend himself in Romans 3:5-8.
If Jesus had actually existed, the gospels would have been written in first person format. Instead, they were written in third person fiction format, often with the supposed thoughts of Jesus. The gospels should also have been original. Instead, Matthew and Luke extensively plagiarized from Mark. The gospels don't even claim to be eyewitness accounts. In fact, there are no claimed eyewitness or contemporary accounts of Jesus - anywhere. All we have are hearsay accounts.
If Jesus had actually existed, at least one of the approximately 30 local historians of the first century would have written about him. No historian of the first century (including Josephus and Philo of Alexandria) wrote about him or his disciples.
Therefore Jesus didn't exist.
The Jesus story also shows extensive similarities to other myths of the time (especially Horus, Mithra, Osiris, and Dionysus). For instance, baptism into the death and resurrection of Osiris washed away sins so the soul could obtain the best place in heaven. Some early Christians attributed these similarities to Satan who went back in time and created the religions that "copied" Christianity.