When we have Christ in our hearts, it is expressed outwardly as a religious act called preaching.

Since we have Christ in our hearts, we can preach Christ to others.

On the other hand, for those who do not have Christ, it can be difficult to do so even with the help of others.

"Do I have much of God's things, or do I have much of what belongs to the world?"

A person's behavior changes according to this.

Then the eleven disciples went to Galilee to the mountain where Jesus had told them to go. When they saw him, they worshiped him; but some doubted. Then Jesus came to them and said, "All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, . . ."

Matthew 28:16-19

Here in this verse, the Bible clearly records the word "baptiziing." Let's read the verse once again.

[B]aptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. . . ."

Matthew 28:19-20

Those who are filled with God's teachings in their hearts can teach the teachings of Christ to whomever they meet and at any time any place.

On the other hand, for those who no longer have God's teachings in their inner world, no matter how much they try to preach, they fail.

When we properly have Christ in our hearts, no matter how small portion it takes, we will be eager to share Christ with whomever we meet. 

However, those who do not have Christ in them are not willing to share Christ with others. 

Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanede you. . . ."

Matthew 28:19-20

This is the greatest command of Christ: "Make every effort to help your neighbors and lead them to the kingdom of heaven."

Only those who have Christ in their hearts can carry out this work.

How can those who do not have God, in other words, those who do not believe in God, carry out this work and save the world?

They can never do this work.

Just as we can give to others whatever we have in us, those who have Christ and His teachings can share Christ with the world and preach His teachings to them. 

We should be able to share happiness with those who are unhappy, give brilliant hope to those who have no hope for the future, and let those who suffer from the agony of life realize that the kingdom of heaven exists and that the present sufferings are not worth comparing with the glory that will be revealed.

Only those who have Christ in thier hearts can carry out this work.