When the documents that make up the Bible were written the authors had their own agenda. They wanted their God to be bigger and more powerful than the gods of other tribes, therefore it was natural they should create a persona for him which reflected that, hence all the zapping of the enemies of the Jews, who saw themselves as God's chosen people.
Sorry, I don't think that's the case. However, for those who have no desire to believe in the bible or at least research the claims, it is a common argument. I suppose there is no way I could be 100% sure the apostles/prophets/writers didn't have their own agenda, I stick with the notion that their words did not reflect their agendas but God's.
John 14:24-27
24He who does not love me will not obey my teaching. These words you hear are not my own; they belong to the Father who sent me. 25"All this I have spoken while still with you. 26But the Counselor, the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you. 27Peace I leave with you; my peace I give you. I do not give to you as the world gives. Do not let your hearts be troubled and do not be afraid.
John 16:12-15
12"I have much more to say to you, more than you can now bear. 13But when he, the Spirit of truth, comes, he will guide you into all truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come. 14He will bring glory to me by taking from what is mine and making it known to you. 15All that belongs to the Father is mine. That is why I said the Spirit will take from what is mine and make it known to you.
Hebrews 1:1-2
1In the past God spoke to our forefathers through the prophets at many times and in various ways, 2but in these last days he has spoken to us by his Son, whom he appointed heir of all things, and through whom he made the universe.