God calls people into different works. In the midst of this diversity, a common thread unites all the work—men ought to do all they do to the glory of God.
How would making your motive match the Lord's motive change how you approach the Christian life (from witnessing to praying to Bible reading and so on)?
It takes a person with strong conviction to be willing to die for a cause. However, the one martyred is not necessarily a mature and complete Christian.