dedicate : 正式用词，指献身于某一崇高事业或目的，也可指把著作题献给他人。
- He has dedicated his life to scientific research.
- The new president said she would dedicate herself to protecting the rights of the sick and the homeless.
devote : 普通用词，指决心把全部身心、精力、时间等献给某一目标，某一个人或致力于某一事业。
- He left the Senate to devote more time to his family.
- She has devoted all her energies/life to the care of homeless people.
- At the age of 25, he decided to devote himself to God.