Just because Reformed Theology teaches that only the Elect will be saved, it does not follow that the Gospel should not be preached and people should not be called to belief. . . . John 3:16.
We are commanded to "always be ready to give a defense to anyone who asks you for a reason for the hope that is in you.” . . . 1 Peter 3:15.
When we are faithful and preach the gospel, it is God preaching the gospel through us. . . 2 Corinthians 5:20.