Why did Jesus leave his disciples forty days after his resurrection? Forty is a significant number in the scriptures. Moses went to the mountain to seek the face of God for forty days in prayer and fasting. The people of Israel were in the wilderness for forty years in preparation for their entry into the promised land. Elijah fasted for forty days as he journeyed in the wilderness to the mountain of God. For forty days after his resurrection Jesus appeared numerous times to his disciples to assure them that he had risen indeed and to prepare them for the task of carrying on the work which he began during his earthy ministry.
Jesus' departure and ascension was both an end and a beginning for his disciples. While it was the end of Jesus' physical presence with his beloved disciples, it marked the beginning of Jesus' presence with them in a new way. Jesus promised that he would be with them always to the end of time (Matthew 28:20). Now as the glorified and risen Lord and Savior, ascended to the right hand of the Father in heaven, Jesus promised to send them the Holy Spirit who would anoint them with power on the Feast of Pentecost, just as Jesus was anointed for his ministry at the River Jordan. When the Lord Jesus departed physically from the apostles, they were not left in sorrow or grief. Instead, they were filled with joy and with great anticipation for the coming of the Holy Spirit.