In Matthew's Gospel, Jesus surprises us with the freeness of the gospel. In Matt 19-20, for instance, we find four consecutive stories strung together by Matthew to show us that in the kingdom of God, the one thing that qualifies us is knowing we don't, and the one thing that disqualifies us is thinking we do.
(1) In Matt 19:13-15, the little children are prohibited from coming to Jesus.
(2) In 19:16-22, the rich young man has a conversation with Jesus about how to attain eternal life.
(3) In 19:23-30, Peter and the disciples wonder what will be left for them, who, unlike the rich young man, have sacrificed all.
(4) In 20:1-16, Jesus tells a parable about workers hired at different times throughout the day and yet are all paid a days' wage.
What's the point? The point is: in the kingdom, the one thing that qualifies you is knowing you don't and the only thing that can disqualify you is thinking you do.
(1) The disciples thought the children needed to qualify with age in order to gain Jesus' attention.
(2) The rich young man thought he needed to qualify with morality ('All these have I kept') in order to gain eternal life.
(3) Peter and co. thought they needed to qualify with sacrifice ('We have left everything...') in order to gain a reward.
(4) The early hired workers thought they needed to qualify with a full days' work, bearing the burden of the day, in order to gain a full days' wage.
They were all wrong. Take the middle two: the young man and Peter. Both viewed discipleship as a financial transaction. The young man decided it wasn't worth it and didn't go for it; Peter decided it was, and did. But both were treating discipleship by cost-benefit analysis. The gospel frees us from this by telling us that all we need is to know is our inherent disqualification and to resist the universal human proclivity to self-resource partial mitigation of that disqualification. How? How can it be that the only thing that it takes to qualify before God is to know we don't? Because Jesus died. We can put it in the terms of the four consecutive stories.
(1) We can have Jesus' undivided attention without qualifying with age or other social prerequisites, because in Gethsemane Jesus was rejected not by age-conscious disciples but by his own Father.
(2) We can have eternal life without qualifying with morality, because upon his ascension Jesus was the one person who could appear before God and really say, 'All these have I kept...'
(3) We can have the ultimate reward without qualifying with sacrifice, because in the incarnation Jesus truly 'left everything' and then on the cross made the ultimate sacrifice.
(4) We can have a full days' wage without qualifying with comparatively more work than others, because Jesus worked the whole day and 'bore the burden of the day' and then allowed himself to be denied his rightful wage by going to the cross.
Do you know your need? If not, you're out. If so, you're in. He died to make it that scandalously easy.