[From https://www.litcharts.com/lit/the-pilgrim-s-progress/part-1-at-the-wicket-gate#summary-207998]
Christian hastily makes his way to the Wicket-gate. When he gets there, he sees a sign over the Gate reading, “Knock and it shall be opened unto you.” Christian knocks several times, asking if a rebel like himself can be admitted. At last, a solemn person named Good-will answers and asks who’s there. Christian introduces himself as a poor sinner who’s fleeing the wrath to come. Good-will gladly opens the Gate.
Good-will gives Christian a slight pull within the Wicket-gate, explaining that Beelzebub, whose castle is nearby, often shoots arrows at those who are approaching the Gate. Then he asks Christian to tell his story. Christian describes everything that’s happened to him so far, including Mr. Worldly Wiseman’s diversion. Good-will tells Christian that nobody’s past misdeeds are held against them when they knock at the Gate, and now that he’s within, he will never be cast out.Beelzebub’s castle is nearby so that he (the devil) can try to destroy sinners who are on salvation’s doorstep, suggesting that, in Bunyan’s view, sinners are in constant danger without Christ’s protection. Now that Christian has made it inside the Wicket-gate, however, he is safe, no matter what he’s done before, and no matter what further dangers he must face en route to the Celestial City.
Good-will then shows Christian the “narrow way,” which was established by the “Patriarchs, Prophets, Christ, and his Apostles,” and is as straight as a ruler. Many wide and crooked paths intersect with it, but if Christian sticks to the straight and narrow path, he won’t get lost. Good-will also tells Christian that when he reaches the place of Deliverance (the Cross), Christian’s burden will fall off.