The most important role or responsibility believers have in this world is to glorify God. The Lord Jesus is the supreme example of this. He could truthfully express to His heavenly Father, “I have glorified thee on the earth: I have finished the work which thou gavest me to do” (Joh 17:4).
As those who have been redeemed by precious blood and belong to Christ, we have a responsibility to “shew forth the praises of him who hath called you out of darkness into his marvellous light” (1Pe 2:9). Paul exhorted the believers at Corinth to be mindful of seeking to glorify God in everything: “Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God” (1Co 10:31).
He reminded us that as those who belong to God, we are obligated to glorify God: “For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God’s” (1Co 6:20). In his letter to the saints at Rome, he appealed to them to be likeminded one toward another, in a Christlike manner, in order that God might be glorified: “That ye may with one mind and one mouth glorify God, even the Father of our Lord Jesus Christ” (Rom 15:6).
Another important role that believers have in the world is that of being a testimony of the saving grace of God, or being witnesses. The Lord Jesus said to His own, before His ascension back to heaven, “Ye shall be witnesses unto me” (Act 1:8). He said of the apostle Paul, “He is a chosen vessel unto me, to bear my name” (9:15).
This is the responsibility and privilege of every child of God. After meeting the Lord Jesus, the woman of Sychar’s well went into the city and witnessed to the men of the city, saying, “Come, see a man, which told me all things that ever I did: is not this the Christ?” (Joh 4:29). The man from Decapolis, out of whom the Lord Jesus cast the legion of demons, began to tell of the great things the Lord Jesus had done for him (Mar 5:20).
Bearing fruit is yet another role of the child of God in this world. The Lord Jesus said, “Ye have not chosen me, but I have chosen you, and ordained you, that ye should go and bring forth fruit” (Joh 15:16). Bearing fruit is manifesting the life of Christ to a godless world.
But we cannot glorify God, or be an effective witness, or bear fruit that gives evidence of the grace of God in those who have been redeemed if we do not understand rightly what our relationship to the world ought to be.
While we may be in the world, we are not of the world. Twice in His prayer to the Heavenly Father, prior to His going to the cross, the Lord Jesus said of His own, “They are not of the world, even as I am not of the world” (Joh 17:14,16).
The Lord has called His own out from the world to be separated unto Himself. In his second letter to the believers at Corinth, Paul quoted from the prophecy of Isaiah (52:11), “Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing” (2Co 6:17). Peter reminds us that, as God who has called us is holy, we too ought to live holy lives. He quoted from the book of Leviticus (11:44), “Be ye holy; for I am holy” (1Pe 1:15-16).
In the first epistle of John, we are admonished, “Love not the world, neither the things that are in the world” (2:15). Paul urges in the book of Romans that we present, or yield, our bodies a living sacrifice to God. He exhorts us not to become like the world: “Be not conformed to this world” (Rom 12:1-2). We are also warned against becoming linked with the world: “Be ye not unequally yoked together with unbelievers” (2Co 6:14).
Just as Israel was the Lord’s “peculiar treasure” (Deu 14:2), so believers today are His peculiar treasure, or “purchased possession.” Peter wrote, “But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people” (1Pe 2:9).
God does not expect us to live our lives in total isolation. We do business in the world, we go to schools, we converse with our neighbours and seek to be a testimony in the communities in which we live. But we must be careful in our associations and guard our affections so that we do not become like the ungodly world around us.
The word “affinity” (which means “alliance” or “relationship”) is only mentioned three times in the Scriptures, but each mention teaches us a very sober lesson regarding our relationship with the world. Solomon, king of Israel, made affinity with Pharaoh, king of Egypt, and took Pharaoh’s daughter for his wife (1Ki 3:1). After that, Solomon took many strange wives, or wives of the nations around, and they turned his heart from following the Lord (11:1-4). Solomon’s affinity with the world brought defection. Godly King Jehoshaphat of Judah joined in affinity with wicked King Ahab of Israel to go to battle (2Ch 18:1) and the result was defeat. In the days of Ezra, the people of Israel joined in affinity with the people of the ungodly nations around them and intermarried among them. This affinity brought defilement to God’s earthly people, whom He had separated unto Himself (Ezr 9:14).
Soon, the day of work, service and testimony will be over, and we shall be raptured into the presence of our blessed Lord and shall be with Him and be like Him forever. In the meantime, we are exhorted to “walk in wisdom toward them that are without, redeeming the time” (Col 4:5). We are to “walk honestly toward them that are without” (1Th 4:12).
Let us, then, as those who have been called from darkness into His marvellous light, act upon the words of the Lord Jesus, who exhorts us, “Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven” (Mat 5:16).
 Bible quotations in this article are from the KJV.