The universal problem
The Bible says that we are born into this world with a nature that is fallen, broken and goes acts against our Creator. One day or the other this nature is evident in one form or the other and that is because of the sinful nature of humans.
Why is it so?
This is due to the original sin of our First Man by the name of Adam, who rebelled against God with his Free Will. So everyone of us who is born into this world inherits that sin and has the sinful nature.
By nature, some time or the other, sin is reflected in our thoughts, words, and deeds. Due to this sinful nature, we go against God knowingly and unknowingly. We lost our connection with our God and all of us are to receive the punishment of sins.
Out of God's love for us, He sent His Son Jesus to pay the price of our sins. Jesus came as a human, lived a sinless life, shed his holy blood, and died for all of us on our behalf. He paid the price on our behalf. Then, He rose again on the third day giving us hope.
For all of us who believe in Jesus, this free gift of salvation from sins is granted and we are made a new creation with a new nature.
God grants us the Holy Spirit to live in us and to empower us to carry out God's Will in our lives. We live the way God is pleased. God helps us to overcome our weaknesses and to be like His Son Jesus.
What if we reject?
For those who have reject God's love shown to us through His Son Jesus, they would be eternally punished. This is what the Bible says.