You see a boy delivering circulars down your road. He knocks and then runs on, and does not trouble himself further.
But there comes a needy man to one door. He has been told to come at any hour on any day, and he knocks.
There is no immediate answer. Shall he turn away? His need is so great that he knocks again. And still the answer is delayed.
"He told me to come," murmured the man. "He told me to knock at his door!"
So he goes on knocking; and by and by the master, who is alone in the house, comes to the door, and with words of welcome, he bids the needy man enter.
And inside the master's house there is a storehouse of blessings! More than the needy man can ask or think.
And the master showers warmth, and love, and food, and riches upon him, so that he goes on his way with every want supplied, and with promises of an endless supply.
How to enter in.
The answer comes back to us, like sweet chimes from afar, in our Lord's own words—
"I am the Door: by Me, if any man enter in, he shall be saved."