Matthew 7:13-14 talks about the straight and narrow road. What is the narrow road exactly?
Well, the narrow road is exactly what the Bible tells us to do. The Bible tells us what we need to do, and our freedoms dwell within those laws. Now, that doesn't mean that we don't have any freedom in our lives. I mean, as long as we follow the laws of the Bible, we can do pretty much anything we want. We just always have to remember the laws given to us. Those laws however, are very strict and don't allow us to stray off of the narrow road.
Okay, imagine you're in a forrest, and there are three roads. two of the roads are wide, and are on the far left and far right of the three roads, and in-between them is a narrow road. There's only a thin line separating them, but they all go to different places. The wide roads both go one way, while the narrow road in the middle go the way you need to go. There's such a thin line separating the two roads, that you know if you even step ever so slightly towards the left or the right, then you'll end up on the wrong path. This is why the way to heaven called the straight and narrow road, because there is no room to step to the side. The way is clear, and you can easily see if you're on the right path as long as you're looking at your map, which was given to us so that we can see how to get to where we're going.
A lot of people like to use the excuse that they're a Christian, and even if they do sin then they can just ask for forgiveness later. They can follow a slightly wider path. That is not the case. Why do you think that people are falling away more and more as time goes by? Because people get so used to going to church and calling themselves Christians, that they forget that they haven't reached the end of the road, and the people in our lives see that even Christians don't follow the Bible. We always have to remember that even though we're Christians, we can't take advantage of that. We can still sin, and if we look like the world then we're not following God's word, and we're not letting our lights shine. It can be so easy to get into the "Christian habit" and just come to Church on Sundays, but then forget what a Christian is on the week days. This is why Christians can be accused of being fake or ridiculous, because sometimes we don't even follow our own views. I'm not saying everyone does this, but I do want to encourage you to not fall into that rut, and to never stop studying so that you can make sure you don't. :)