There are no instructions in the Bible as to how to handle the physical body after death. While cremation has pagan roots, we do not see the prohibiting of the practice mentioned in Scripture.
There are many examples of burials throughout the Bible. In Genesis 23:9, Abraham purchased a burial site for Sarah and himself, and Joseph requested that his bones be carried out of Egypt (Genesis 50:25). In the New Testament, ground burials were noted for John the Baptist (Mark 6:29), Lazarus (John 11:17-19) and Jesus (Mark 15:46). There are no mentions of cremation in the New Testament.
When it comes to the handling of a loved one after death, which option to choose is a very personal decision. And at the resurrection, it will not make any difference. God will raise the body according to John 5:28-29, and it will become a new and glorious body (1 Corinthians 15:35-54 and Philippians 3:20-21)!
If you are facing this decision, whatever you do, seek the Lord and desire to hear from Him. Then, act according to the peace in your heart.