From Macarthur's Romans 1-8 commentary, p. 348:
"After a businessmen's luncheon at which I spoke, a man said to me, 'I've been in this group for a long time, and I'll tell you how I think you can get to God. You see, there is this long stairway, and at the top there is a door and behind it is this guy Jesus. What you really want to do is try to make it up the stairs and get through the door and then hope Jesus lets you in. As you're on your way up the stairs, you've got all these preachers and movements cheering you on, but you just continue going up the stairs your own way. I call it the stairway of hope. That's what I think the gospel is.'
"With a heavy heart I replied, 'Sir,you cannot be a Christian. What you said has nothing to do with the gospel, and your stairway to heaven is hopeless. You need to depend on Jesus Christ alone for your salvation. You have no idea of what it means to be saved, and you cannot be on your way to heaven.'
"A person cannot invent his own way to God, no matter how sincere his efforts might be. God has established the only way to come to Him, and that is the way of faith in His Son, Jesus Christ. And saving faith in Jesus Christ is built on God's revelation about Him, not on men's ideas about Him. There is divinely-revealed content to the gospel, and the person who rejects or circumvents that content gives unmistakeable evidence that he is not truly seeking God's kingdom and His righteousness."