Assignments from God are completed FROM identity, not FOR identity. Once you know that you are already a child in his kingdom (by grace through faith), he equips you as an ambassador to complete assignments.
Ephesians 2:10 For we are God's handiwork, created in Christ Jesus to do good works, which God prepared in advance for us to do.
An assignment from God has to do with those good works you were created unto. An assignment has to do with those works God has prepared for you to do. An assignment is something God wants you to do as an ambassador of his kingdom. God may have multiple assignments for you throughout your life, some are fulfilled in a day, some are walked out over a lifetime.
God has things he wants you to do, don’t you want to do them?