Read Romans 6:23
23 Sin pays its servants: the wage is death. But God gives to those who serve him: his free gift is eternal life through Jesus Christ our Lord. (JBP)
When we give gifts at times like birthdays or Christmases or anniversaries, they are not given as rewards for services rendered. When someone gives me such a gift I do not presume they are prizes for good behaviour or outstanding achievement. I am given such gifts because of who I am, not because of what I may have done. I am a child, a parent, a partner.
We get prizes or rewards for good conduct, for special achievement. Nothing wrong with that, but these are not gifts like the other sort. I have not necessarily deserved a gift; I have usually done something to deserve a prize or reward.
Our text reminds us that because of our rebellion against God we deserve death: separation from God. It is a perverse sort of reward for what we have done or not done. Eternal life with God, everlasting togetherness with him, is not like that at all. It is a free gift given to us not because we deserve it but because of who we are. Which is much loved human creations.
Life forever with God is ours not because we are good people, or because we are churchgoers who say our prayers, or because we are crusaders for morality, or because we know our Bibles well. It is ours out of sheer love and grace. A gift, not a prize.