2 Cor. 10:13-18 (ESV)
But we will not boast beyond limits, but will boast only with regard to the area of influence God assigned to us, to reach even to you.  For we are not overextending ourselves, as though we did not reach you. We were the first to come all the way to you with the gospel of Christ.  We do not boast beyond limit in the labors of others. But our hope is that as your faith increases, our area of influence among you may be greatly enlarged,  so that we may preach the gospel in lands beyond you, without boasting of work already done in another's area of influence.  "Let the one who boasts, boast in the Lord."  For it is not the one who commends himself who is approved, but the one whom the Lord commends.
Boasting gets a bad rap in Christian circles. But Paul doesn’t hesitate to boast. He is confident in the Gospel, and he boasts about it. There is no reason we should not do the same. We are Christians we have the sure word of God that our sins are forgiven. We can take that to the streets. We can walk tall with our chests out, knowing that our Lord is Lord of all. We can take pride in Jesus, and not be ashamed of the Gospel of Christ. Who cares what the world thinks. We have God, because he has us. He saved us from our sin, he snatched us from the grip of death, he stomped on the head of Satan. We are conquerors in Christ. Let us boast in him. Show our pride and take on anyone who might slander him. There is nothing wrong in boasting in the Lord.