Most of the answers I have given and will give to the questions asked come from the Bible. This raises the question of whether the Bible can be trusted. This is a huge question and takes a lot of thought. I would argue that the real issue is not that the bible is true, but whether we can trust the Gospel accounts about Jesus. It is Jesus who we claim to be God the Son, hence the real issue is whether the Gospel’s are true. The wider question about the reliability of the OT (which we consider to be reliable), I will not answer here. There are really good reasons to accept the basic account of Jesus life in the four Gospels are true.
1. They read like eye-witness accounts in that there is general agreement on the outline of what happened with minor discrepancies (virgin conception/birth – ministry of teaching [love/faith-based living] – miracles – prophetic – healing – crucifixion – resurrection – ascensions).
These minor discrepancies make it unlikely that the accounts are the result of collusion i.e. if they were, then the minor discrepancies would have been removed.
2. The similarities between the first three Gospels in particular do not suggest collusion but that in some way Matthew, Mark and Luke were dependant on each other. This is called the Synoptic problem. Most scholars believe that Mark was the first gospel and Matthew and Luke used Mark plus other material they had including possibly a source called Q (quelle). Some others believe Matthew was first and that Mark and Luke are dependent on it. All agree John is an independent source.
3. The cross-referencing to Greco-Roman and Jewish history (e.g. Herod, Pilate [cf. Tacitus, Pliny, Josephus]), archaeology and geography stand up under scrutiny i.e. the dates and references in the gospels-Acts play out against other histories. This suggests that they are reliable.
4. The history which followed in which we see Christianity burst forth (see Acts) and spread in 300 years across the Roman world, often clashing with its mother-faith, Judaism. This suggests that Jesus really lived, died and rose again! If he hadn’t his followers would not have been so determined in the face of persecution.
5. The preparedness of Christians in those 300 or so years to die, often in the worst imaginable way, for their faith strongly suggests that it is for real. Why would such people die for a lie?
6. The power of the Gospels to change lives since the time of Christ is an existential argument for their authenticity
I conclude that the Gospels are an honest recollection of the experiences of the first disciples. As such they record the most amazing and pivotal moments in human history from the incarnation of God the Son in the person of Jesus, to the most extraordinary 3 year ministry of a living human to the ultimate demonstration of Jesus godship, the resurrection. So why not read them.