That is an excellent point! It is Almighty God who calls all men to repentance and faith in Christ. It is the Holy Spirit who is in the world to convict the world of sin, righteousness and judgment. All we are called to do is speak the truth, preach the Gospel, be instant in season and out, and trust the Lord to open hearts to receive the truth. No soul was ever won to saving faith in Christ at the end of a sword. Jesus said all would know we are his disciples by our love one for another. This should be a HUGE clue to those who might be considering conversion to Islam.
As Peter amply demonstrated,we can make people very hard of hearing depending on how we wield the 'sword'.(Ephesians 6:17,1 Peter 3:15)