Liberal Christian, Do-Gooders Have Got It Wrong.

So many of this group have a horror of earthly punishments - others accept that they must exist but try to tone them down. (The sheer inconsistency of the logic here, defies all comprehension.)
Such people seemingly believe that 'witnessing' to criminals and 'giving them an example of Christian love' is the solution too all our/their problems.
Proper punishments come into play FIRST. These are not an alternative. Unless you grossly misuse John 8 to try vainly to make a case, you will fail totally to put together any scriptural argument for this thinking.
Divorce the punishment from the 'Christian love' and you are then onto something!

No human being can see into the heart of another. Too many are the examples of criminals 'converting' in the hope of 'a better deal' - as proven necessary by their alleged remorse. Christians are not meant to be stupid!

It is only AFTER the implementation of earthly punishments that it is possible to start to give trust.

Christians being seen as weak, lily-livered and naive does NO favours to the spread of The Gospel whatsoever.