Ecclesiastes 9:4-6 says:
…he who is joined with all the living has hope, for a living dog is better than a dead lion. For the living know that they will die, but the dead know nothing, and they have no more reward, for the memory of them is forgotten. Their love and their hate and their envy have already perished, and forever they have no more share in all that is done under the sun.
One of the ways in which we have hope while we are alive is that we can repent and turn to God. When we die it is too late.
Therefore, as the Holy Spirit says,
“Today, if you hear his voice,
do not harden your hearts as in the rebellion,
on the day of testing in the wilderness,
where your fathers put me to the test
and saw my works for forty years.
Therefore I was provoked with that generation,
and said, ‘They always go astray in their heart;
they have not known my ways.’
As I swore in my wrath,
‘They shall not enter my rest.’”
Take care, brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God. But exhort one another every day, as long as it is called “today,” that none of you may be hardened by the deceitfulness of sin. [Hebrews 3:7-13]