Mimi,
It's just the way they translated it. I found 3 verses where it's translated "rose again". Here are the verses and the Greek word used in each (the first word is used in the first two verses):
G1453 ἐγείρω egeiro (eg-ei'-ro) v.
1. to waken
1Cor 15:4 And that he was buried, and that he rose again (woke) the third day according to the scriptures: KJV
2Cor 5:15 And that he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again (woke). KJV
It probably would have been better if they translated it lived again.
G450 ἀνίστημι anistemi (an-is'-tay-mee) v.
1. to stand up
1Thess 4:14 For if we believe that Jesus died and rose again (stood up), even so them also which sleep in Jesus will God bring with him. KJV