You have part of your question correct; it was written by man. The Bible was written by 40 different men who wrote the 66 books of the Old and New Testaments over the course of 1,500 years.
The part you have incorrect is that God was not involved with writing His Holy Word. Let’s take a look at what the scriptures have to say about it.
20Most important of all, you must understand this: No prophecy in the Scriptures comes from the prophet’s own understanding. 21 No prophecy ever came from what some person wanted to say. But people were led by the Holy Spirit and spoke words from God. 2 Peter 1:20-21 (ERV)
God used those 40 different men to write the 66 books of the Old and New Testaments, but as the scripture tells us they were led by the Holy Spirit to write what they wrote. Literally it was dictated to them by the Holy Spirit and they wrote it down. Let’s look at another scripture.
16All Scripture is given by God. And all Scripture is useful for teaching and for showing people what is wrong in their lives. It is useful for correcting faults and teaching the right way to live. 17Using the Scriptures, those who serve God will be prepared and will have everything they need to do every good work. 2 Timothy 3:14-17 (ERV)
Who gave us the Bible? The Bible tells us that ALL scripture was given by God, not man. Every word of the Bible was verbally and fully inspired by God; it is flawless and contains no mistakes. The Bible is the supreme and final authority for all Christian faith and conduct.
If you really think about it, this is the only book written about our Lord God, His love letter to us. What would make you think God would allow man or woman to write it for Him?
I hope that answers your question my friend. I encourage you to pick it up and start reading it, and find out for yourself how much God really loves you.