No person truly knows that answer. Many religious folk believe that they do and are quite firm in that belief, but that does not make it so. We know for a fact what happens to their bodies, but questions of an afterlife will always remain unanswered.
Your body will eventually decompose when you die and that is all there is too it. There is no heaven or hell. Even if there was, you need your body to feel right? No body no feelings. For this reason, what you do while you are alive is what is most important since there is nothing else after that.
At death we simply return to dust as can be seen at Genesis 3:19 "For dust you are and to dust you will return." The dead are not conscious, nowhere did God tell Adam that his soul or spirit would survive, nor was eternal torment nor life in heaven mentioned to Adam. Ezekiel 18:4 says that the soul that sins will die. So your relatives are simply laying as if in sleep. The only hope is the one mentioned by Jesus in John 5:28,29 and also mentioned in Acts 24:15: that of a resurrection to in a paradise earth, or the heavenly hope extended to a few.
If you are a believer, scripture says:absent from the body-present with the Lord-2 Corinthians 5:1-8. And your soul joins Him. At the rapture--your soul and your body join Jesus in the air!-1Thess4:13-18. John 3:14-15. Everyone who has this hope(certainty) Will strive to live a pure life.1John3:3-9 I once read the book:90 minutes in Heaven..... Then i thought perhaps i should know about Hell/and found the book:23 minutes in Hell! Oh my, i dont want any part of that! now read Matthew25:41.-46
As the Catechism says, death puts an end to human life as the time open to either accepting or rejecting the divine grace manifested in Christ. In other words there are no opportunities to grow in holiness, no second chances. After we die we immediately stand before the judgement seat of Jesus and He will reward us based on how we have lived our lives, on how we have responded to the blessings and graces He gave us. This is called the particular judgement, because it refers to each of us individually. If we have died in the state of grace, we will go to Heaven or spend some time in purgatory. If we have died in a state of mortal sin, we will immediately go to Hell. Many of our culture are afraid of death. Why? Probably because they do not really grasp the meaning of life. We need to prepare ourselves for death by living our lives as Jesus calls us to, by loving Him with all our strength and loving our neighbors as ourselves. Many of the great saints longed for their time on earth to come to an end so that they could go home to be with the Lord. They were unafraid of death because they understood the purpose of life and lived it: They loved.
Genesis 2:19 "All your life you will sweat to master it, until your dying day. Then you will return to the ground from which you came. For you were made from the ground , and to the ground you will return." (Living Bible). Romans 5:12. "Therefore sin came into the world through one man and death through sin, so death spread to all men because all men sinned." (Revised Standard Bible)