The reason newly converted people don't come is that we (most churches) no longer practice the Great Commission.
Matthew 28:19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.
The Great Commission is a three-fold command (Ecclesiastes 4:12 And a threefold cord is not quickly broken.)
1. Teach them (the Gospel)
2. Baptize them (into the membership of a bible teaching local church)
3. Teach them (continuing action) to observe all things commanded of them.
I once talked to a fellow pastor who was complaining his soul winning team won as many as 25 people to Christ every week but seldom did more than 1 or 2 ever come to church.
I asked him what type of followup program he had. He said, "None! If they are really God's children they will find their way to God's house."
A couple months later his wife had a new baby. I stopped in to congratulate him but he was in a hurry. I asked him where he was going in such a hurry. He said, "To the hospital to bring my wife and new baby boy home!"
I said, "Well, if he is really your son he will find his own way home!" He just stood there and stared at me with his mouth open.
Baby Christians, like baby people, need a lot of extra care. Including inviting them to church, picking them up and driving them to church. Including them in the fellowship of the church. Taking them out to lunch after church. And doing the same thing over and over and over again until coming to church on Sunday morning becomes a new, spiritual, habit. We have forgotten the key to church growth:
assimilation. Making the new convert part of our church.
But we have adopted the "Billy Graham method of evangelism." We preach the gospel to them, then, when they get saved we send them right back to their old life, old church, and old friends without bothering to complete the last two commands of the Great Commission.
By the way, keeping 1/3 (winning them) of the Great Commission is 33%. That is an "F" in every school I ever attended.
Keeping 2/3 (wetting them) of the Great Commission is 66%. Still an "F" in every school I ever attended.
We need 3/3 (worshiping with them) of the Great Commission to get that 100%. And that's how you get an "A."
The most interesting part of Sanderson's bio on their church's web page is his statement, "Thousands have been saved, many have been baptized."
Thousands saved and "many" baptized? How many Steve? I know your average Sunday morning attendance is under 100. So, if "thousands" have been saved, where are they? Did you forget the last two parts of the Great Commission?
I guess you get an "F" in Great Commission Keeping!