Romans 11:29 (AMP)
For the gifts and the calling of God are irrevocable for he does not withdraw what he has given, nor does he change his mind about those to whom he gives his grace or to whom he sends his call.
There is an assurance in the “Call” of God. When God calls (makes a request or demand) you or gives you a gift (a notable capacity, talent or endowment) it is impossible to revoke and not capable of being changed. Even God says he will not take it back or remove his call.