cast all your anxiety on him, because he cares for you

This verse concludes the thought begun in verse 6. Christians must humble themselves under God’s mighty hand, trusting Him to exalt us at exactly the right time. We must quit the work of seeking our own glory in order to accept the work of serving and submitting to others. Then, when the time is right, our God will use His mighty hand to exalt us. 

Source: Bibleref