God has a calling on each man’s life. Furthermore, He enables men to fulfill their appointed work. Man, however, must be strong and DO the work.
Man must spend his strength on things that matter. In doing so, we must focus our efforts upon the right things while working through and by God's power.
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)?