You shall inherit the land by lot according to your families; to the large tribe you shall give a larger inheritance, and to the small tribe you shall give a smaller inheritance. Wherever the lot falls to any man, that shall be [the location of] his [inheritance]. According to the tribes of your fathers (ancestors) you shall inherit. – Numbers 33:54
After reading some important passages about the casting of lots in the Bible, it seems that the reasons for the practice were to help in decision-making, find out God’s will on a particular subject/topic, and to fairly close a matter between two or more parties. The practice is no longer necessary due to having God’s completed Word and the Holy Spirit to guide us into all truth.