There are many different ways Mormonism and the Bible can be compared. One way is looking at how each describes the size of the gap between God and humans and then how that gap is bridged.
Very briefly, Mormonism makes that a relatively small gap. It does that in two ways. First it teaches about a God whom humans can understand. The God of Mormonism was once a man, is now an exalted man, limited by a body – not omnipresence, omniscient, etc. Secondly, Mormonism has a high view of humans. We were God’s spirit children; sometimes referred to as gods in embryo. We have the divine potential to become gods ourselves. Both of these factors, a God that once was a man and humans that become gods, create a gap between God and humans that is not that great.
The Bible teaches something totally different. It describes a God that is far beyond human comprehension. He has no beginning and no end. He is omnipresence, omniscient, omnipotent, etc. His very nature of three distinct persons but one being boggles our minds. Secondly, the Bible speaks in stark terms about the devastation sin has wrought on the human race. It describes people as blinded by sin, dead in sin, enemies of God. It says that, “all have turned away, they have together become worthless; there is no one who does good, not even one.” (Romans 3:12) The result is that the Bible pictures the gap between God and humans as huge.
All this is foundational to the main and pressing question of how this gap can be bridged. Mormonism teaches that bridging this gap depends on the efforts of both God and man – something that it says is possible because the gap is not that big. “For we know that it is by grace we are saved, after all we can do.” (2 Nephi 25:23) This doesn’t even describe a picture of two parties meeting half-way. Rather this describes humans taking the initiative, doing all they can, expending all their effort to bridge the gap – and then, only after they have exhausted all their resources, does God get involved and help out.
Again the Bible teaches something totally different. Because the gap between God and man is so huge, it takes divine initiative and divine effort to bridge. Not only that, but humans couldn’t do anything because they were dead in sin, “they have together become worthless.” Therefore God did it all. Jesus came not as a teacher or example to show people what they had to do to save themselves. Rather he came as a substitute to do it all for us. He kept all the commandments perfectly and gave us the credit for it. He died a horrible death as payment for our sins. He didn’t wait until we had expended all our effort – he didn’t meet us halfway – he came all the way to us and did everything to bridge the gap. “For it is by grace you have been saved, through faith – and this not from yourselves, it is the gift of God – not by works, so that no one can boast.” (Ephesians 2:8-9)
To sum it up: Mormonism puts much of the burden of bridging the gap on humans. The Bible gives God all the credit for completely bridging the gap himself. To God be all praise and glory.