I have recently started reading “The Way of the Master” By Ray Comfort and Kirk Cameron. Ray Comfort seems to be biblically sound and grounded in the word (at least so far).
He talks against preaching a shallow “God loves you and has a wonderful plan for your life” message.

“Instead of preaching the good news that sinners can be made righteous in Christ and escape the wrath to come, we have settled for a “gospel” that implies that God’s primary purpose in saving us is to unfold a “wonderful plan” for our lives: to solve our problems, make us happy in Christ, and rescue us from the hassles of this life. Make sure you understand the difference”.
One of his main points perhaps even the principal point of his book is the Principle of using the Law to reach the lost.
(Mark 10:17-21, Proverbs 6:23 The commandment is a lamp and the law a light. Gal 3:24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. Or clearly in Romans Nay, I had not known sin, but by the law.)
I think this is a vital point that we should agree on in terms of “methodology” in reaching the lost. However way we do it – we must use God’s word and we must also use his law. How are the unsaved to know that they are sinners if they don't truly know what sin is?: For sin is the transgression of the law (1 John 3:4)
Ray Comfort quotes Spurgeon in support of this principle: (in speaking of preparing the soil of the heart with the plow of the law) “One other reason why this soil was so uncongenial was that it was totally unprepared for seed. There had been no plowing before the seed was sown and no harrowing afterwards. He that sows without a plow may reap without a sickle. He who preaches the gospel without preaching the Law may hold all the results in his hand, and there will be little for him to hold.”