'Mightily' in the Bible

Then the Spirit of the Lord will come upon you mightily, and you will prophesy with them, and you will be changed into another man.

When they came to the hill [Gibeah], behold, a group of prophets met him; and the Spirit of God came on him mightily, and he prophesied [under divine guidance] among them.

The Spirit of God came upon Saul mightily when he heard these words, and he became extremely angry.

Then Samuel took the horn of oil and anointed David in the presence of his brothers; and the Spirit of the Lord came mightily upon David from that day forward. And Samuel arose and went to Ramah.

Now it came about on the next day that an evil spirit from God came forcefully on Saul, and he raved [madly] inside his house, while David was playing the harp with his hand, as usual; and there was a spear in Saul’s hand.

Then Saul said to David, “May you be blessed, my son David; you will both accomplish much and certainly prevail.” So David went on his way, and Saul returned to his place.