What if the gravity on Earth was more or less intense?

Well this could caused in two ways.
1. Earth has more or less mass (more importantly density.)
2. The co-efficient of gravity (G) is bigger or smaller.

To be quite honest, if we accept that there is life on other planets then we probably have to accept that more or less massive, or more or less dense planets can support life.

But for number 2, the question is completely different, not the effect on life, but the effect on the universe, with a suffientely big enough G the big bang would have immediately (if it even managed to  happen) lead to an immediate big crunch, too small and the universe will just expand for ever, planets would probably be larger, but if the universe survived without too extreme conditions for roughly 10 billion years then we would probably have life.

As you might have noticed a lot of dinosaurs where HUMONGOUS  some scientists suggest that for them to have survived and not collapsed under their own weight ( as large whales do when they are out of water or in water not with the right salt content) gravity would have to be weaker, a possible reason for this would be that the Earth was hotter then and so it was bigger then it cooled and contracted increasing it's density.

If you mean the effect on humans, then you could look to the space station where humans live in low gravity for extended periods of time, muscles waste, bones weaken but it's not really a problem until they come back down to normal gravity.

Well, think of it this way:  How much do you want to carry around?  If you weigh 120 lbs now and gravity doubled your weight, what kind of changes would occur in your physiology to support 240 lbs?   Your bones would grow thicker, your muscles stronger and you may even increase your red blood cell supply.  Your caloric needs would rise to meet the added work done to combat gravity.

Now if the opposite were true and gravity decreased, I suppose your bone structure would decrease along with the strength of your muscles.  Since you do less work just moving around, you would need fewer calories.  I don't know if you would actually grow taller though.  Height may make life more difficult...it changes the leverage of your skeletal system and increases the distance over which your heart has to pump blood.

without gravity we all would be floating,and if everything went back to the original content that god made we all would be fine