Here's a good way to remember how many books are in the Old and New Testaments (not my idea - I got this in a Walk Through the Bible session many years ago): Count the number of letters in OLD and TESTAMENT -- 3 and 9. Put them together, 39. There are 39 books in the Old Testament. How about the New Testament? Count the letters, still 3 and 9. There are 3 x 9 = 27 books in the New Testament, and thus a total of 39 + 27 = 66 books in the Bible. (I thought that was clever.)
All Christian beliefs are based on the Bible, except in the case of Catholicism. Martin Luther was concerned with the Catholic Church’s practice of selling indulgences to obtain salvation. He correctly believed this was in conflict with the Bible. In 1517 Luther started the Protestant Reformation when he nailed his 95 theses to the church door in Wittenberg, Germany. In response to this movement, at the Council of Trent in 1545, it was affirmed that Catholic tradition is equal in authority to the Bible. This raises a dilemma since Catholic tradition is sometimes contrary to the Bible. I believe the Bible is the final authority even though understanding the Bible is sometimes difficult and subject to interpretation.
There are different interpretations of the same biblical passages, which is why we have different denominations. I've been doing Bible study for 40 years. Certainly, I'm not an expert, so what I write will be my (simple minded) understanding. I pray that if I say something that is false, it will be quickly forgotten since I want you to only believe what is true.
One more item before I get to a passage. What is the difference between grace and mercy? Some people say they are the same, but many years ago in Sunday school, I learned the following:
Grace is a free, underserved gift from God.
Mercy is God withholding from us punishment that we do deserve due to our sins. In short, Grace is getting what we don't deserve (e.g., salvation), mercy is not getting what we do deserve (punishment).
A great passage to memorize:
Ephesians 2:8-10 (NIV)
8 For it is by grace you have been saved, through faith--and this is not from yourselves, it is the gift of God--
9 not by works, so that no one can boast.
10 For we are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do.
In a nutshell, salvation or being saved refers to having our sins forgiven (grace) so we can live with God forever, and faith in vs. 8 refers to trusting in the death of Jesus to pay the penalty for our sins (He took the punishment we deserve). One thing that distinguishes Christianity from just about all other religions is that Christianity believes salvation is by grace and not by works. Think of a balance scale. Most religions believe that if you put your good works on one pan and your sins on the other pan, you will be saved if your good works outweigh your sins. In essence those religions are telling Jesus that he didn't need to die, because people can save themselves by being good enough. In that case, how would a person ever know when they had done enough good deeds? Can you imagine how frustrating it would be wondering if you had met your quota? There is no way we can earn our salvation. It is priceless. It cost Jesus His life and we could never do enough to pay for His sacrifice.
There's no work we can do to save ourselves. The work was done by Jesus when he died on the cross. Sometimes this is described as "Doing vs. Done." We don't do the work; the work has already been done by Jesus. Good works are important (vs. 10), but they are not an avenue to salvation. We do good works out of gratitude to Jesus and our desire to serve Him.
When you ask someone if they will go to heaven when they die, often the answer is, "I think so because I've been a good person." This is a misunderstanding. I imagine such people are thinking of the balance scale. Salvation is not based on our goodness, but on the goodness of Jesus.
Someone once asked me how we can be sure we are saved. My response was that our assurance comes from the authority of the God’s Word – the Bible.
Consider this verse:
1 John 5:13 (NIV)
13 I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.
Notice that John did not say, so that you may think or hope that you have eternal life, but rather so that you may KNOW that you have eternal life.
Finally, I want to say that we can’t make excuses for not knowing that God exists. There is a great passage in Romans 1 starting in verse 16, but I will just quote verse 20:
Romans 1:20 (NIV) 20 For since the creation of the world God's invisible qualities--his eternal power and divine nature--have been clearly seen, being understood from what has been made, so that men are without excuse.
I’ll close with this beautiful passage from Psalms:
Psalm 19:1-4a(NLT2) 1 The heavens proclaim the glory of God. The skies display his craftsmanship. 2 Day after day they continue to speak; night after night they make him known. 3 They speak without a sound or word; their voice is never heard. 4 Yet their message has gone throughout the earth, and their words to all the world.