The second essay is "First Efforts" (1959). It is a selection of Russell's philosophy diary when he was a teenager.
The third is "Why I Am Not A Christian" (1927). Lots of stuff here...
First, Russell attempts to define what it means to be a Christian. He is right in saying it is a confused matter (and that was eight years ago! It is only more confused now...).
Russell attempts to find a set of doctrines which define Christianity. This can be effective, Christians have a set of beliefs which you must hold to be "orthodox" (small 'o'). However, we should ask, "Where do these doctrines come from?" and look to the logical backing behind them. Russell fails to do this, probably from ignorance.
Ultimately, it is irrelevant whether one calls oneself "Christian". The Bible makes it clear, there will be a judgment between true and false Christians (sometimes referred to as the "Sheep/Goat" judgment -- Matthew 7:21-23).
So, what matters is whether Christ will call you Christian. This is made clear in 1 John. We must agree with God that we are sinners, repent (turn from) a life of sin, and trust in the death and resurrection of Christ to pay the price for our sins and guarantee us eternal life. Then, read the Bible (as the source of God's instructions for us) and do what it says.
So, the doctrines vital to Christians are not just a random set of dogmatic statements (as Russell seems to believe). They are logical propositions which follow from a complete reading of the Bible, with a view to interpreting the Bible in terms of itself, and using the clear passages to shed light on the unclear (and not being dogmatic about what is truly unclear).
Russell lists the following doctrines:
- Belief in God and immortality (the first seems obvious, the second follows from the Bible -- God says there will be a resurrection to life with God, and one to punishment).
- "[B]elief that Christ was, if not divine, at least the best and wisest of men." (I would go further, Jesus said He was God. If that is not true, then He would not be good or wise at all.)
- Belief in Hell. Interestingly Russell says an act of Parliament removed this from Christian doctrine. I wasn't aware that Parliament was superior to God... Anyway, the Bible clearly says there is a Hell, and that everyone deserves to go there. It is only by the grace and mercy of God, and the death of Christ to pay the penalty of sin, that any may be saved.