A fundamental doctrine of Christanity is that Jesus is a mediator and therefore Christianity is idolatry.
This is a core and fundamental doctrine
5 For there is one God, and there is one mediator between God and men, the man[a] Christ Jesus, 6 who gave himself as a ransom for all, which is the testimony given at the proper time. 7 For this I was appointed a preacher and an apostle (I am telling the truth, I am not lying), a teacher of the Gentiles in faith and truth.1 Timothy 2:5-7 (ESV)
Timothy is clear here, that not only is Jesus a mediator, but the function of his mediation is to have given himself as a ransom.
We begin with Job 33. The contention for a mediator is found in v. 13 and defined in the following passages:
This vehicle is defined as mediator for the purpose of atonement, salvation, or forgiveness:
Some people may look at this and insert Jesus into the passage, but verse 29-33 prevents this as a misinterpretation:
Therefore, the statement of mediation in the Hebrew is consistant with the Christian concept of mediation in terms of atonement – even though it is not a form of vicarious atonement – the purpose of God's mediation here is to remove people's sins. This is thus defined as within the realm of God's standard relationship with people in a pre-Christian world.
Given the above that the fundamental purpose of the mediator is atonement, forgiveness, salvation – and the vehicle by which is the ability to communicate with God (ex. Job 33:13) we may now examine verses which discuss the nature (the vehicle and process by which) atonement, or salvation, or forgiveness from sin is achieved in the Hebrew.
6 Thus says the Lord, the King of Israel and his Redeemer, the Lord of hosts: “I am the first and I am the last; besides me there is no god.
7 Who is like me? Let him proclaim it.[a] Let him declare and set it before me, since I appointed an ancient people. Let them declare what is to come, and what will happen.
8 Fear not, nor be afraid; have I not told you from of old and declared it? And you are my witnesses! Is there a God besides me? There is no Rock; I know not any.”Isaiah 44:6-8 (ESV)
God's word is very clear that there is no other being than himself with the function of a “mediator” in the sense of sin and atonement. It is specified there is no “rock”, no “other” by which the function of mediator is fulfilled. In fact the idea here is not that God fulfills a role of mediator, but that there is no such role (no rock) by which it is achieved – God himself is the savior.
Exodus 20:3 states “lō yih·yeh- lə·ḵā ’ĕ·lō·hîm ’ă·ḥê·rîm ‘al- pā·nā·ya,”:
This is a deep reading of the commandment proper as it was taught to the Israelites, in Hebrew, by God. The term elohim here means any such god, gods, or even God – before his face – and the standard reading here is that since God is omnipresent, even in one's mind, one may not even entertain the concept that any such power may exist in the universe, which is capable of challenging God.
Thus the concept that there is some personage, or being, or object, or anything other than simply stated, God the Father – who is responsible for sin and atonement, is a heresy. Especially such a concept by which one must direct prayer or worship for any reason, not limited to being merely for the purpose of transmitting the prayer to God.
The standard example here is the story of the Golden Calf; Exodus 32:1 is received as, “Since the people feared that Moses would not come down from the mountain, the people gathered themselves together against Aaron and said to him, 'Quickly, make us gods who shall go before us to replace Moses, the man who brought us up out of the land of Egypt; for we do not know what has become of him.'”