I think the mystery and process is not described because it is different for every person. Charles Finney was a lawyer one day, transformed by the love of God and went on and revival followed him every where he went. Charles Wesley was already a Christian and it was in the fear of dying he realised he wasn't saved. If it was described the world would be full of people imagining transformation instead of going through it.
Jesus was not lying when he said narrow is the way and few find it. He said it was new wine skins for new wine and that the old ones could not contain what he was talking about. It has to be the only thing you want and you will give everything up to find it. There are many stories of people who struggled with giving up their lives, money, family all of these things become a reason why not to surrender to God.
Fresh water and salt water do not mix. Theology runs round the never ending circle of how we can be saints and sinners at the same time.
It is not possible
And this is the sure faith that Christ is in us, in all men and it is the power to save and transform you. If you think it will happen in the future...why? you already have Christ. If you think it's something God gives you then rejoice you already have it from God. It is within you, you can never un have the light till the day you die.
No reason to doubt that God is not there, no reason to doubt the power is not there. Jesus showed the way and now we follow
Jesus said I am with you till the end of days
When Governments go on unjust war the people rise up and demand peace
When sexual immorality is everywhere the people rise up and choose abstinence
When the Government let the rich steal all the money the people rise up and demand that it is shared with everyone
I am the light of the world and I will be with you always