I realize our society is big on relativism, humanism, new agism and existentialism, but somewhere down the line one has to deal with absolutes and reality. Here are some absolutes: God created. Part of His creation is humanity. God told the first humans certain things about His creation. He gave them boundaries and set up consequences if those boundaries were violated. The first humans chose to violate those boundaries (sin). God followed up on what He said. Those first humans died - physically and spiritually. Their offspring continued in the same manner as their ancestors and the results were identical - physical and spiritual death. Though not all of them experienced spititual death. A few, those who chose to put their faith (confidence, trust) in God, have eternal life, following their physical death.
You've heard this before: For God so loved the world that He gave his only begotten Son to die for our sins. Those who chose to believe, trust, have condidence in this reality would not be condemned to eternal death. Instead, they will receive eternal life. No one is exempt. Nobody can claim that they are sinless. Even if you can avoid all the outward and obvious sins, your own thought life would condemn you. We have a choice: Either we continue down the path that leads to eternal death or we chose to have faith that Jesus is the Messiah / Savior / God the Son - and have life after we physically die.
Another reality: Throughout the Old Testament God plead with people to turn away from the idols / gods that they worshipped. Today we don't necessarily bow down to manmade carvings, but we do worship ourselves, our money, our wealth, and power. He said that there is only one God; only one savior. He doesn't know another. In the New Testament Jesus was constantly referred to as Savior. There are at least three instances where the Father, Son, & Holy Spirit were mentioned together - and given equal standing. Though the word Trinity never appears in the Bible, it is plainly obvious that the Father, Son, & Holy Spirit is God (singular). Since God will not contradict Himself, there cannot possibly be 3 Gods. In an over simplification of an example, I can be viewed as a father. I have four children. I also have a father. I also have a brother. I Fulfill several roles. But I am one person.
One last reality: When reading the Bible among many things it gave a clear purpose to our existence. Building upon what Noah, Snowy Falcon, and Buckeye have said, we are to worship / glorify God; be an example to and for other people with Christian faith; and be a reflection of God such that the non-believers will see their need to put their faith in Jesus.