Balance matters in everything; there is nothing in which it does not matter. Extremes are never good. So is with evangelism. It is because of its nature. Evangelism is basically relating the gospel to the sinners (Luke 5:32). So, an evangelist cannot do it without getting close with them. As he gets closer with them, deeper does he get into dangers. So, he needs be in balance so that he would not be swallowed by sin. He needs listen to what the Bible teaches to keep balance in his ministry.
On the one hand, it teaches that Christians have to come near the sinners to preach the gospel. We are peacemakers, that is, reconcilers between God and sinners and ambassadors of Christ Jesus. Actually if we tried to avoid all sinners or sinful environments, we would have to go out of the earth (1 Cor. 5:10). We should be different from some religious people who isolate themselves from the worldly people and live secluded among themselves. Rather we have to go among the sinners. Going into “all the nations” in the Great Commission can be understood in this sense. Jesus himself did so (Luke 5:30-32). Apostle Paul did and taught so (1 Cor. 9:22; 1 Tim. 1:15). And it is sure that other apostles and Christians also did so (cf. Acts 1:8).
However, that does not mean that Christians may associate with sinners in their sins. Sharing sinful life is never an evangelism. Scripture also commands that we should not be yoked with sinners unequally (2 Cor. 6:14). In other words, we should not forget why we are there among them—to lead them out of darkness through the truth (Acts 26:18). Paul’s “becoming everything to everyone” has to be understood under this principle (1 Cor. 9:22) as he absolutely followed it (9:23, 27). If we forget the purpose and lose ourselves, we would be like those who throw their holy things to dogs and their pearls to swines (Matt. 7:6). They will swallow up or trample our gifts and turn back and tear us apart.
For us not to lose the balance in evangelism, we have to be wise as serpent as we have to be innocent as a dove. For to that, the most important principle is that we should not turn to the left nor to the right but we have to go only toward the truth (Jos. 1:7). Also we should not try to be righteous for our own (Rom. 10:2-3). As we try to be righteous for our own, we may get tempted by the worldly desires. Then, we may not render a service to the Lord but a disservice. Therefore, we have to hold on to the message, “Jesus Christ and him crucified” (1 Cor. 2:2). Without carrying it, no matter how it may sounds good it is not a balanced evangelism. The message is the saltiness of the salt and sweetness of a candy. It has to season all the things that we think, speak, and do in our lives as well as evangelism. As long as we do so, we will not lose balance and our evangelism will do good to sinners as well as to ourselves.