There is a difference of opinion about what this actually means. But from a clear understanding of the Gospel of Matthew, it can mean only one thing: it means to become a disciple of Christ.
Some will say that it simply means to believe in Him, as in for salvation. But I believe that Matthew, among other the other gospel writers, teaches that following Christ means to become His student, His disciple; it's more than just the faith that brings salvation. There are several places where I believe Matthew differentiates between a believer and a follower. They are, in fact, two different entities.
Yes, following Christ is more than just believing. Do I believe that believers will get into heaven? I certainly do. For those from the Parable of the Denarius (Matthew 20:1-16) who answered the Master's call, even though they worked only a short while and produced little fruit, still received the denarius, which represented eternal life. Why were they given as much as the others who had worked longer and harder? Because the Master of the Vineyard is generous. In the end, payment wasn't given based on performance, but on the fact that the workers responded to the Master's call.
Still, there are those of us who have agreed to work longer and harder. But rest assured, there are other rewards for us, as well. The Parable of the Wedding Feast further demonstrates this principle. Those who responded to the call made it 'in' to the Wedding Feast, but those who were the servants and slaves (disciples), received personal interaction with the Bridegroom. And isn't that what you want? I know it's what I want.
Being a disciple of Jesus means to be a dedicated learner; one bent on learning and doing exactly what our Master has said and taught. It means that we focus ourselves squarely on Jesus, Himself; His teachings and His deeds. Not Paul and not the OT. We must learn and implement the exact curriculum that Jesus prescribed. That curriculum is the complete basis for the book of Matthew. And if you want to follow Christ, Matthew stands ready to help you.
I want to help you see how Matthew has intended to accomplish this. My hope is to show you how the First Gospel works as a discipleship manual, help you use it in your life, then turn you loose to show others that Matthew stands ready to disciple them, as well. My hope is to see faces of all colors, all over the world, enjoying this rich discipleship treasure known as the Gospel of Matthew for it was never intended to be read as a biography; no, it was intended to be used as a discipleship textbook.