From Biblical Truth Resources:
Judas was chosen to be one of the twelve apostles to serve God and be a witness to the Gospel and revealed truth. He obviously was partaking of this truth, but rebelled and became an apostate—thus frustrating the loving plans of his Master: Acts 1:25; Mt. 10:2-4; Lk. 6:12-13; Mk. 3:14-15. The reasons why the Twelve were chosen are given below. If the Lord Jesus chose to bestow extended labor of preparation upon one whom He certainly foresaw would fall of the intended mission, it would appear that an unwise and inconsistent choice was made. Judas had no authority, he merely “became a guide to those who arrested Jesus” (Acts 1:16).