There are two ways we know God. The first way we know God is just by looking at creation. If you just look at yourself and the wonderful creation around you, you begin realizing that everything you see around you couldn't have come by accident. Therefore there must be a Creator. The second way we know God is our conscience. The Gentiles, although they do not have the Law, do by nature things required by the Law. This means that each and every one of us has a moral compass, known as a conscience. Unfortunately though, this natural knowledge is not an excuse to get us to heaven, as our consciences are imperfect as the result of sin. some try to live good lives with the hope of earning heaven by works. Some are even atheists. Many would rather look for God in religion to try to appease him with their works. The purpose of the natural knowledge is to lead us to seek God. Not to be justified into not seeking and believing in God and that He can save us.
What was the purpose of the Law? The Law's purpose is to show us that we have sinned. Sin is missing the mark of perfection. It is breaking God's Law. Imperfection cannot be in the presence of a perfect God. Make just one mistake, you are no longer perfect and don't deserve heaven. The Law is not enough to get you to heaven because those who rely on the Law are under a curse, because those who do not continue to do everything written in the Law are cursed. Those who rely on the Law receive eternal death in Hell when they die because they have sinned. Again, what is the purpose of the Law? To show our sins.
But hope is not lost! This is where the Gospel comes in. What does the Gospel show us? The first thing the Gospel shows us is that Jesus was perfect. For just as through Adam's disobedience many were made sinners, so also through Christ's complete obedience will we be made righteous. The second thing the Gospel shows us is that Jesus took our sins and died for us. Christ redeemed us from the curse of the Law by becoming a curse for us. Even when we all deserve punishment, Jesus died in our place. The third thing the Gospel shows us is that Jesus gives us His perfection. Jesus opened the Way to know God by giving us his righteousness so that we may have a relationship with God. Our imperfection cannot get us to God. Only Christ's perfection can. The Gospel is what is enough to get us to heaven, because it shows us that we have a Savior. Those who believe the Gospel will receive eternal life. But those who don't receive it will be condemned.
The Gospel is a free gift to all of us. If you are going the wrong direction due to your imperfections, it's not too late! Turn around and receive Christ's gift of eternal life today!