2 Corinthians 6:1-2 [1] We then, as workers together with him, beseech you also that you receive not the grace of God in vain. [2] (For he said, I have heard you in a time accepted, and in the day of salvation have I succored you: behold, now is the accepted time; behold, now is the day of salvation.)

While you are alive [your now] is the only time for you to be able to be saved.  You cannot wait until the “White Throne Judgement” and expect to be reprieved from eternal death and separation from God as it will be too late.

For those who have not heard of Jesus and salvation, the answer is the same.  While one is alive if the only time that one can be saved through Jesus’s payment of the sin penalty.  Unsaved humans have God’s creation that screams his existence and power also, humans are created with a conscious an in bread knowledge of God, but most often ignore such.  If a human desires to be saved even without hearing about Jesus, they can pray to God and repent of their sins.  God has the power to then let them know of Jesus either via the Holy Spirit or sending someone to let them know about Jesus.  ALSO, although God wants everyone to be saved through Jesus, he has the right [fair or not] to save whom he chooses and not save whom he chooses.  He can make pottery for good or bad.