In other words, all who are called in this sense are also justified. It is a call that works effectively to bring the elect to faith and that cannot fail. If someone is called in this way by God, they will believe. Since not everyone believes, not everyone is effectually called by God. Therefore, salvation is a result of God's choice of whom to call.
Election is unconditional.
This must mean that God works effectively in each person He has chosen to ensure that they come to faith. If a person does not come to Christ, it means that the Father did not choose to give him to Christ. You do not become a sheep by believing. You can only believe if God has chosen to make you a sheep. This means that if God sends His word to change a person's heart, the heart will be changed.