The Great Commission commands us to make disciples, not just converts. But how we make disciples is going to be influenced by how we do evangelism.
How do we try to bring people into the kingdom? We present all the benefits of being a Christian. We talk about the quality of the fellowship, the joy of having a purpose, the hope that we have with God active in our lives.
All these things are true but that is not what Jesus taught.
“Whoever does not bear his own cross and come after me cannot be my disciple.For which of you, desiring to build a tower, does not first sit down and count the cost, whether he has enough to complete it?Otherwise, when he has laid a foundation and is not able to finish, all who see it begin to mock him,saying, ‘This man began to build and was not able to finish.’Or what king, going out to encounter another king in war, will not sit down first and deliberate whether he is able with ten thousand to meet him who comes against him with twenty thousand?And if not, while the other is yet a great way off, he sends a delegation and asks for terms of peace.So therefore, any one of you who does not renounce all that he has cannot be my disciple.” (Luke 14:27–33 ESV)
Jesus wanted people to come in with their eyes open. He wanted them to know what discipleship is and wanted them to reflect on whether they were able to commit.
What would happen if we really put this into practice? Instead of making it as easy as possible for people to transition into the kingdom, what if we explained first what discipleship entailed?
I know that things could easily get muddied with our understanding of salvation by grace. They are not contradictory, even if some people may get confused. We enter into the kingdom only by grace. But disciples of Jesus are still expected to live a certain way. See the letters of James and 1 John for examples. Still, this would require an effort in clarity.
If we explained what discipleship is during evangelism, it is possible that less people would respond. But it is also likely that less people would fall away because they knew what they were getting into.
It is also possible that full disclosure about discipleship would make Christianity more attractive. Many people are looking for a challenge and do not just want the easiest way.
However we integrate discipleship with evangelism, we do need to take this teaching by Jesus seriously. There is a cost to discipleship and people are going to discover this sooner or later.