What was the purpose of the ancient custom of casting lots?

God gave the ancient Israelites the ritual of casting lots as a way to ascertain His will in uncertain matters (Num. 33:54; I Sam. 14:42; I Chron. 24:5). Casting lots is a solemn appeal to God in a doubtful matter. God inspires the process so as to reveal His divine will. This was still practiced in Christ’s time. His disciples cast lots to determine whom God was selecting to replace Judas Iscariot. (See Acts 1:15-26).

After Pentecost in A.D. 31, the Bible makes no further reference to the casting of lots. The apostles relied upon the Holy Spirit to directly guide them. Please read Acts 2 and John 16:13. You may also wish to read Acts 6:1-8; 13:1-3; 15:19, 28; and 16:6.

As in early New Testament times, God, by the power of His Holy Spirit working through His chosen ministers, reveals His will to His Church, on important matters for which Scripture offers no specific command.