Luke 24:49 Behold, I send the Promise of My Father upon you; but tarry in the city of Jerusalem until you are endued with power from on high.
When the Holy Spirit becomes part of our lives we are filled with the same power that created the entire universe. Jesus knew the job we had been given was beyond our own strength and so He commanded the disciples to make sure they received power from on high before they attempted to fulfill His plan. After ten days of waiting in the Upper Room, the disciples were baptised in the power of the Holy Spirit on the Day of Pentecost (Acts 2). From that point those early disciples were completely transformed men and women.
The most dramatic turnaround was Peter, who just days before was a discouraged, dejected fisherman who felt he had completely failed Christ, having denied him three times. Yet, after being baptised in the Holy Spirit he fearlessly stands before a crowd of devoted religious people proclaiming Christ, bringing three thousand of them to Christ in a moment! All the disciples literally turned the world upside down with their preaching, miracles and healings after they had been baptised in the power of the Spirit. This power is the same that Samson used to defeat hundreds of warriors single handedly. This is the same power that healed the sick through Jesus. This is the same power that raised Jesus Christ from the dead after three days. This exact same power dwells inside each of us. We can never again admit to being powerless in the face of trouble. Jesus promised the power of the Spirit to all those that hunger for Him. God will satisfy our hunger for Him with the infilling of the Holy Spirit.