Sin leads to death, but sin can be forgiven through the sacrifice of Jesus Christ. But to make use of the sacrifice of Jesus Christ and hence gain eternal life we need to associate ourselves with it.
"for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins." (Romans 3:23-25)
This explains the point of Jesus’ sacrifice. We have all, from time to time, turned away from doing what is right, which makes us sinners. This puts us on the road to eternal death, but Jesus has made a sacrifice of himself to allow our sins to be forgiven. Associating ourselves with this sacrifice is a process which contains several different steps.
Faith is not only believing but acting on that belief. Faith alone will not lead to salvation. That requires action as well.
Sin can be forgiven by the death and resurrection of Jesus. But we need to associate ourselves with that death and resurrection. This is done by baptism, a full immersion into water.
Salvation from sin, and therefore from death, requires four steps:
Belief - It is necessary to understand the basics of the Gospel and to believe that these are true.
Repentance - It is necessary to change the direction of one’s life and make a commitment to following the teaching of God through the Lord Jesus Christ.
Baptism - It is necessary to be immersed in water in order to become associated with the death and resurrection of Jesus Christ.
Live Faithfully - It is finally necessary to continue to live the Gospel. This involves teaching the Gospel to others and living a life which attempts to follow the teaching of Jesus Christ.