"I Am the Lord, and besides Me, there is no savior." -Isaiah 43:10
Often times we think of God as separated between the Old Testament and the New Testament God, and not just the laws as divided. We often times see God as separated between the merciful God who sent His Son, and the God who will send the majority of people to hell on Judgment Day (Matthew 7:14). However, there is one God, and He is a perfect God. So why are there so many differences? What evidence do we have for this?
The most commonly used passage in reference to this is Mark 12:29 which states that the Lord our God is one God. He is not distributed into several aspects like the Greek or Roman gods. He is not a symbol, but He is one God. In the time in which this was written, Rome was in rule, and you don't have to know a lot about ancient history to know that Romans had a lot of gods. They had a god for wisdom and war, a god of creation, a god of nature, a god for everything. One of the biggest contrasts between Jesus and where He spent his time while He was here on earth, was not only the Jews but the amount of gods worshiped. Several went from hearing about a different god for every little thing to only one God. In his sermon on Mars Hill, Paul preached about an “unknown god” (Acts 17:23). Everyone was so accustomed to several different gods that the thought of there being only one God baffled them. But this is what Christianity is: a contrast (Matthew 5:13-16). We need to keep this in mind as we journey on towards heaven.
We see in 1 Timothy 2:5, Isaiah 43:10-11 James 2:19, Mark 12:29, and several other passages that there is one God. But what does that mean to us? Well, as I said previously, people often view the God of the New Testament and the God of the Old Testament as different. The law was different, so God must have been different. This is not the case at all, though. See, while the laws may have changed, but right and wrong never did. It was still wrong to murder, it was still wrong to commit adultery, to steal, to covet, etc. While some aspects of the law did in fact change, a lot of things that were wrong back then were wrong because of other reasons. For instance, there were certain kinds of meat that the Jews weren't allowed to eat such as pork, rabbits, camels, etc. As time went on, we learned that a lot of these animals, and that if not prepared properly, they could have death-causing diseases. A lot of things that they were commanded to, and not to do were simply because they didn't know that those things could cause disease. Doesn't God do that today? Aren't there some things that we as Christians may not understand, but God has a reason for each and every law.
Right and wrong has not changed. God has not changed, simply the law has adjusted to what was necessary at the time. We see that a lot in the Bible. In 1 Corinthians 11:6 we see that women are to cover their heads when they pray, but that was because it was custom to those people at that time. In that specific culture, covering your head was a sign of reverence and of respect. In other places, a woman covering her head was a sign of disrespect and in some, even, prostitution. The same applies to the Old and the New Testament. The laws changed not because God changed, and not because what was right and wrong changed, but because the time and the cultures did. This is not to say that we can change the law in order to meet our own wants and desires or to add or subtract from it (Revelation 22:19) but that if God so desires, He can change the law if the situation calls for it, but only if the situation calls for it. Some things are wrong because they're wrong, while some things are wrong simply because God says so.
In Isaiah 43:10, God says “I am the Lord, and besides me there is no savior.” Often times we look towards our work, our school, or other earthly passions for glory. We look to those things for salvation, and for justification for our actions. We believe that our lives will get better if we just have the next something that we want. However, the world is filled up with a whole lot of somethings that end up being a whole lot of nothings. Mark 8:36, “For what does it profit a man to gain the whole world and forfeit his soul?” (ESV) and Matthew 6:24, “No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money.” Without God, we would have no chance of being saved. Without God, we could try everything this world has to offer and still never be saved. There is one God, and one salvation. John 3:3, “Jesus answered him, 'Truly, truly, I say to you, unless one is born again he cannot see the kingdom of heaven.'” Without God and without the sacrifice that He made for us, we wouldn't be saved and there is no denying that no matter how much you try.
So how does this apply to our every-day lives as Christians? How does this change our daily walk towards heaven? Every day we have temptations. We hear the perspective of others, we have our own points of view, and sometimes we can get confused. Sometimes it seems as if there are multiple things going on and that there are several different paths to heaven. However, there is only one narrow gate (Matthew 7:13) and we cannot start to veer off into random trails, no matter how similar or how much better they appear. It's important that we as Christians keep the one faith, read the one Bible, and follow the one God, even if it appears that there are multiple roads.