Therefore we were buried with Him through baptism into death, that just as Christ was raised from the dead by the glory of the Father, even so we also should walk in newness of life. Rom 6:4
No matter what happens to your body after death – whether you are buried in a grave or cremated, the most important decision is what you do in life.
Accepting Jesus as Savior and following up with baptism is symbolic of the death, burial, and resurrection.
You are buried with Him through baptism.
Jesus said, “Do not marvel at this; for the hour is coming in which all who are in the graves will hear His voice and come forth — those who have done good, to the resurrection of life, and those who have done evil, to the resurrection of condemnation.” John 5:28-29
Do not let the word grave convince you of a hole in the ground. The word means a place of interment, whether a grave, tomb, or sepulcher.
For someone that has been cremated their interment could be an urn or the four winds.
God is able to resurrect all no matter how long dead or the condition of the body.
Don’t be so worried about your body after death, be more concerned with your soul before death.