Calling
Calling is God's summons to people through his revealed word and gospel, and in some passages God's appointment of particular people to a role or purpose. The meaning of calling must be determined by the passage's audience and context.
Expanded explanation
God does not leave humanity without a witness or a summons. The gospel announces what God has done in Christ and calls people to respond. That call is sincere because God is not pretending to invite people whom he has made unable to answer. At the same time, calling is not always a technical synonym for conversion. God called prophets, Israel, apostles, and churches to particular purposes. Reading each passage carefully prevents the word calling from being used as a shortcut for an entire system of salvation.
Context
Calling should be distinguished from election, invitation, appointment, conversion, and final salvation. A passage may describe God's call to a mission, Israel's calling, the universal proclamation of the gospel, or the response of those who believe. Context determines which claim is being made.