The gospel produces in Christians both humility and boldness. Read what Tim Keller says:
“When the gospel ‘comes home’-humbling and affirming you, it turns every believer into a natural evangelist…Evangelism happens because of a) the humility of the gospel. The gospel (unlike religious moralism) produces people who are not disdainful and contemptuous towards those who disagree with them. Also, it happens through b) the affirmation of the gospel. Because of the reality and joy of Christ’s love, we are not as concerned what others think. The gospel brings a gentle boldness.”
“The gospel makes us neither self-confident nor self-disdaining, but both bold and humble at once. To the degree I am still functionally earning my worth through performance (i.e. to the degree I am still functioning in works-righteousness), to that degree I will be either operating out of superiority or inferiority. Why! Because if I am saved by my works, then I can either be confident but not humble (if I am living up) or humble but not confident (if I am not living up). In other words, apart from the gospel, I will be forced to be superior or inferior or to swing back and forth or to be one way with some people and another way with others. I am continually caught between these two ways, because of the nature of my self image.
So the gospel humbles me before anyone, telling me I am a sinner saved only by grace. But it also emboldens me before anyone, telling me I am loved and honored by the only eyes in the universe that really count. So the gospel gives a boldness and a humility that do not “eat each other up” but can increase together.” Link