Matthew 28:18-20
[18]And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
[19]Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
[20]Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.
The task of evangelism is a very heavy task and honestly it impossible humanly. No human being can claim the ability to transform and heal another human in their own power. Divine intervention is necessary.
In the above Scripture Jesus Christ invites believers into a partnership with him. He clearly states His contribution to this relationship; Power , not just any power , but divine power.
He then goes ahead and stipulates what his partner is required to do. That is to go and makes disciples in the entire world.
He assures the believer of his continued presence even as he leaves the earth.
Bible scholars call this divine arrangement the great commission. It stipulates core reason why believers need to reach out to the unbelievers here are seven reasons why we share the love of the finished work of the cross
1) Non Believers need to be freed the bondage of sin
John 8:34
[34]Jesus answered them, Verily, verily, I say unto you, Whosoever committeth sin is the servant of sin.
The apostle John explains that the non believer is a slave of sin. He is a servant of sin . That is he has no ability to stop sining on his own strength. He/She requires supernatural intervention to be free from this bondage. This is where a believer is required to bring the 'Good News'.
2)Non Believers are Spiritually Blind
2 Corinthians 4:4
[4]In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
The apostle Paul explains to the Corinthian Church, that the god of this world (satan) has blinded the unbelieving mind so that they are unable to comprehend the spiritual reality of the benefits of the glorious gospel of Jesus Christ. The non believer cannot on their own understand that Jesus Christ is the express image of God. Hence a believer with the help of the Holy Spirit needs to shine this light through the gospel of Jesus Christ.
3) Non Believers need Salvation
Luke 19:10
[10]For the Son of man is come to seek and to save that which was lost.
The main reason why Jesus came down here on earth was to seek and save mankind lost in sin and vanity. In the last chapter He assigns the church to continue to seek man through evangelism as he saves them through the power of the Holy Spirit.