Our culture promotes the tolerance in all areas of life. Dishonoring God and disobedience to His decrees were once considered taboo are now being looked at through the lenses of tolerance; however, when it comes to the message of the gospel, the sense of tolerance is neglected. We must recognize that the hope of all mankind depends on their relationship with God and the message of the gospel is necessary regardless of the opposition we face.
We should take some time to define few terminologies which will mentioned in this piece.
Christendom
The term ‘Christendom’ has come to be particularly applied to that period of Christian history in which Christian religion was an integral and fundamental part of the social order. It has been more loosely used of the Christian world as a whole. On the narrower interpretation, to be a full member of society one also had to be a member of the church. The turning-point in Christian history which changed the relationship of the church to the state from one of hostility or grudging acceptance to one of privilege and mutual affirmation, was the conversion of Constantine, c. 312 ad. The arrival of a Christian emperor in time changed the whole relationship of the church to the state. The possibility of a society which conformed to Christian values seemed to be open to the whole of society and not just to the church within it. Thus in practice as well as in thought much more attention had to be given to the respective roles and relationships of the church and of the state as different aspects of the one Christian social order
New Dictionary of Theology: C ~ Christendom
The Gospel
We must look at the message of the gospel apart from the notion of ‘Christendom‘. Simply put, the gospel is, what God has done for man kind through Jesus Christ. God has made a way for humanity to be made right with God by place their faith in the work of Jesus Christ which was finished on the Cross. The gospel reveals to us the power of God for He alone is able to deliver from the bondage of sin–all who believe.
I am obligated both to Greeks and non-Greeks, both to the wise and the foolish. That is why I am so eager to preach the gospel also to you who are in Rome. For I am not ashamed of the gospel, because it is the power of God that brings salvation to everyone who believes: first to the Jew, then to the Gentile. For in the gospel the righteousness of God is revealed—a righteousness that is by faith from first to last, just as it is written: “The righteous will live by faith.”
Romans 10:14-17 NIV