The only ultimate motivation is the happiness or the glory of God (DR 130 - 132; MVG 235; LP 323). (religion-online.org)
If you think about it, I think that the ultimate motivation behind all types of sin is an attempt to manage the pain of believing «I am not.» (sarahbessey.com)
This was the ultimate motivation to try candying ourselves — chiles, of course. (fieryfoodscentral.com)