No it a a case of do it the Bible Way or the highway. The Bible way is this.
LAW TO THE PROUD & GRACE TO THE HUMBLE
People that disagree with this disagree with the Bible.
Thiis a very bold statement. Let's see if you prove it.
When I preach to the elderly I will preach in a nursing home, with a tract, or a one on one conversation. The Bible is quite clear on the principle of law to the proud and grace to the humble.
LAW TO THE PROUD
Lk 10:25-37
MK 10:17-22
GRACE TO THE HUMBLE
JN 3:1-21
These are simply examples of how your theory works. They are not proofs, they are not stated principles, they are just examples of how Jesus did personal evangelism. He did it other times when He did not even mention the law. So you have not proved your point.
Paul also followed the principle of law before Grace. After warning that God would judge humanity by the moral law Romans 2:12. The law is written on the conscience of men v.15. Therefore when we do evangelism our evangelism must go towards the conscience rather than the intellect or the emotions. Modern evangelism often goes to the intellect or the emotions rather than the conscience. Satan will do all that he can to get Christians not to discover this secret key that has been lost over the years.
Again, you have not proved your point. Rom. 2:12 is not talking specifically about evangelism, nor is verse 15. What tells us how to do evangelism? The Great Commission in Matt. 28, Mark 16, Luke 24, John 20 and Acts 1. You have not yet referred to any of these passages, so your theory of evangelism is unproven until you do. You have no warrant at all to say as you did, "People that disagree with this disagree with the Bible."
One thing you are missing here is that it is not us, it is the Holy Spirit who "convicts of sin, righteousness and judgment" (John 16:7-11). When we proclaim the Gospel that Christ died for our sins and rose again, the Holy Spirit does the work in the heart, not us. We may use various Scriptures as we give the Gospel, but we cannot convict of sin. Only the Holy Spirit can do that.
Again, the idea that if we disagree with your way we disagree with Scripture does not hold water when considering the book of Acts. Peter did not preach law on Pentecost (2:14-39). Peter did not preach law when the lame man was healed (3:12-26). Peter did not preach law to the Sanhedrin, yet they were "cut to the heart" (5:29-33). Paul did not specifically preach law when he witnessed cross-culturally on Mars Hill (17:22-31; he preached against idolatry, but not from the Law). Need I go on?