A few colleagues and I have recently been engaging Tony Gurule of Ratio Christi on matters pertaining to Christian theology.
I want to bring up 3 points that have stood out in some of the conversation I've been involved in and/or seen.
Distinction between Being and Person, in the Bible?
Firstly, I did ask Tony Gurule for a BIBLICAL distinction between being and personhood as Trinitarians believe God is One Being and 3 Persons.
Tony could not furnish such a distinction. In that case, I would say to Tony and other Trinitarians that you are getting this distinction between being and personhood form Church Tradition - thus not being true to the concept of Sola Scriptura (drawing from Scripture alone). Tony would argue it's was philosophy and not church tradition. However, this is where the semantics come in.
The distinction is not taught by the Bible - even experienced Trinitarian apologists like James White cannot come up with a Biblical distinction.
Where did the distinction come from? And what is it?
Tony is right, it's philosophy. I'm right too, it's church tradition. It can be both. It is both :)
Christians from the 4th century onwards began to develop their philosophy about God in argument with those they deemed to be heretics and in interaction with material in the Bible - the NT especially. So the philosophy of 3 persona came about through the Church. It's Church tradition.
Now Trinitarian Christians have a framework (a philosophy aka Church/Creedal tradition) with which they view the Old Testament and New Testament.
The Catholics are upfront in admitting to Church tradition, evangelicals such as Tony Gurule are reticent to do so as they openly profess to be Sola Scriptura.
However, it's obvious Church tradition has influenced Evangelicals. Not only with regards to the philosophy of the Trinity but also with regards to the Books in the NT. The Church decided which books were to be included in the NT canon - that's to say later Church tradition tells evangelicals and other Christians which books are "inspired" - the original authors did not claim inspiration. In some cases there was controversy. For instance, the Book of Revelation was mired in controversy as the Church could not decide whether to include it in canon initially.
My point here, although Church tradition seems like a dirty concept in certain evangelical communities, there's no escaping evangelicals are prone to Church Tradition when it comes to the canon and the Trinity belief.
Trinitarians may be told the Trinity is clearly deduced from the Bible but if it was so clearly taught in the Bible and so easily to come to through exegesis (rather than eisegesis) then why were there centuries of squabbling - sometimes vicious squabbling over these matters?
Can Jesus sin according to Christianity?
I personally do not believe that He was able to sin (from the human nature of course).
Side note: There are differing opinions on this topic though. The two terms are impeccability and peccability. Some people believe that Jesus was not able to sin, and He did not, but other people believe that He was able to sin, but He did not. So, although the two groups differ on the "could," both groups believe that He did not.
Hold on, Tony and other Christians are in opposition to Matthew. Matthew does not appear to have the same belief - he seemingly believes Jesus could be tempted (thus inferring he believed Jesus could sin):
Then Jesus was led by the Spirit into the wilderness to be tempted by the devil. Mat 4:1
The same applies to Mark, he too seemingly believed Jesus could be tempted and thus presumably could sin:
and He was there for forty days, being tempted by Satan. He was with the wild animals, and the angels ministered to Him. Mark 1:13
How can one who cannot sin be tempted? It seems authors of Mark and Matthew had different views to Tony and other evangelicals.
Heresy: separating the two natures
Tony seemingly separated the idea of Jesus' dual natures. He stated "the human nature is completely distinct and separate".
Perhaps Tony was unaware, in separating the two natures one falls into the ancient "heresy" of Nestorianism. Admittedly, Nestorius took it to the level of believing Jesus was two persons but Tony's "separating" of the two natures is akin to how Nestorius came to the view Jesus was two persons. Christian theologians believe the two natures are actually unified. Here's RC Sproul warning against separating the two natures:
We can distinguish the two without separating them. But when the human nature perspires, it is still united to a divine nature that does not perspire. [What is the Trinity, RC Sproul, Loc397]
The teaching do not mix nor separate the natures of Jesus is one which Trinitarian theologians use to keep their flock away from Eutyches' monophysite understanding and Nestorius' Nestorianism.
A message to Trinitaian Christians from a Muslim
If you'rea Trinitarian, I suspect you will have a few doubts about Trinitarian theology. Explore those doubts.
Ponder upon the Trinity dilemma in this video. This is a powerful point to get people asking questions about the Trinity belief.
The Trinity Dilemma
Historically, the early Church Fathers did not believe in the Trinity concept.
Speaking of the pre-Nicenes, New Testament scholar Robert M. Grant perspicaciously explains that "Christology of [early Christian apologists..is essentially subordinationist. The Son is always subordinate to the Father who is the one God of the Old Testament." [Dr Edgar G. Foster]
Just to show how late the Trinitarians formed the final formulation of the Trinity doctrine, as late as 380 AD the Church still had not unanimously agreed to include the Holy Spirit as a divine being. Through Gregory of Nazianzen, as late as 380, we see there was a running debate as to what to believe about the Holy Spirit. How can there have been a Trinity teaching passed down through apostles concerning the Holy Spirt if Christians were undecided on what to believe about the Holy Spirit?
"Gregory of Nazianzum could still say in 380, Some of our theologians consider the Holy Spirit to be a certain mode of the Divine energy, others a creature of God, others God Himself. Others say they do not know which opinion they ought to accept, out of reverence for the Scriptures which have not clearly explained this point." [Sourced from Patrick Navas]
It's well known Jesus' statements were not of a Trinitarian but what you may be unaware of, Paul and Peter made statements which seemingly refute the idea of the Trinity:
In 1 Cor 8:6 Paul spells out the identity of God and identifies Him as the Father:
yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live.
In Acts 2:36 Peter is purported to have said:
"Therefore let all Israel be assured of this: God has made this Jesus, whom you crucified, both Lord and Messiah."
Notes from Sean Finnegan's interview with Patrick Navas: Is the Trinity Biblical
Tovia Singer: Does the New Testament Teach Jesus is God?