Just the Basic Gospel?

1 Cor. 2:1  And I, when I came to you, brothers, did not come proclaiming to you the testimony of God with lofty speech or wisdom. 
1 Cor. 2:2  For I decided to know nothing among you except Jesus Christ and Him crucified. 
1 Cor. 2:3  And I was with you in weakness and in fear and much trembling, 
1 Cor. 2:4  and my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power, 
1 Cor. 2:5  so that your faith might not rest in the wisdom of men but in the power of God. 
(ESV)
I find this passage very interesting, and I think it is a good reminder of how we should be witnessing to others.

"And I, when I came to you, brothers,"
Paul went from Athens to Corinth, and stayed with Aquila and Priscilla and made tents with them, for they were tent makers. On the Sabbath, he went and taught and witnessed and probably debated in the synagogue. Paul stayed in Corinth for a year and a half before leaving for Syria (Acts 18:1-18).

"did not come proclaiming to you the testimony of God with lofty speech or wisdom."
When Paul came to Corinth, he preached the Gospel: you are sinners, Christ came to save you from your sins, repent and you shall be saved.  He didn't come to prove that he was smart or that he was better than than those to whom he spoke.  He came to share the simple truth. Now, I think the key word is "simple," as we will see in the following verses.

 "For I decided to know nothing among you except Jesus Christ and Him crucified."
Paul preached the very simple Gospel - nothing more nothing less - Christ died for you.  That is how he witnessed.  When he came to Corinth, he witnessed, not using deep doctrine, but he witnessed using only the Gospel: You are a sinner, you need to be saved, and Christ came to save you.

" And I was with you in weakness and in fear and much trembling,"
Why would Paul, one of the pillars of Christianity, be afraid?  Was he afraid of people hurting him? Was he afraid of being rejected?  I think not.  I think he was afraid of letting Christ down; that, in some way, his doctrine might not be correct, or that he might say something he didn't mean to say. He is afraid of leading others astray by accident.

"and my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power,"
The Gospel doesn't make sense logically.  Why would a God send down his own Son to die for sinful men?  You can't figure it out through logic because it just doesn't make sense. Then, you might ask why anybody would believe it, and here is my answer to you: "demonstration of the Spirit and of power."  The Holy Spirit has so much power to move men's hearts, that you can't imagine it.  He uses His infinite power to save men, and move their hearts.

"so that your faith might not rest in the wisdom of men but in the power of God"
If our faith rested in the wisdom of men, it would draw away from the power of Christ and His death. Not only that, but it wouldn't make much sense, and we would be fools since what we believe does not make sense without the Bible to explain it.  If Paul had been able to convince people based on logic, or based on reasoning, or because of his eloquence they would not have stood faithful; they would have reasoned themselves to false theology and doctrine. When people are saved by God's power, that is where they will always look for wisdom, or at least that is where they should look for wisdom, because God promises us that He will grant us wisdom.

Jas. 1:5  If any of you lacks wisdom, let him ask God, who gives generously to all without reproach, and it will be given him. 
Jas. 1:6  But let him ask in faith, with no doubting, for the one who doubts is like a wave of the sea that is driven and tossed by the wind. 

So next time you witness to somebody, keep in mind that the basic Gospel is all you need to use, because it will show His power, and it will be to His glory.