If you hear over and over the professional slander against the alien races, you probably won't believe it, until you witness something yourself.
Then you believe the slander.
The leading governments cannot cover up the aliens.
They can only threaten the aliens to stay away, spread slander about alien life and the humans who have personal contact, and manipulate and discredit information through the media and UFO groups about them. 
It is impossible to overestimate the magnitude of the government conspiracy against the alien races and true human knowledge of them.
The government (secret government) is committing crimes against the alien races and against humans who have alien contact.
What they are hiding is what they themselves are doing.
They do not want to accept what the other races are offering to improve the quality of life on Earth because suffering is lucrative.
The government is doing all it can to prevent true information from being known to the people, and generating and spreading false information to maintain confusion.
All races believe in the same one God because God teaches at every world.
No other world has the kind of dogma and manipulation of power and money in government and religion that we do. 
It is possible that the government might be getting ready to let out a new wave of disinformation.
For example, first the government says, if there were any aliens, we would know it.
Then they will say, we know there are aliens and they are a threat.
Since the government can't hide the aliens, they will make us believe we are under attack.
The proof will be when buildings blow up and people disappear.
Earth Craft vs ET Craft
When the military shows its crafts, that makes them able to claim the alien crafts are their's too.
Alien crafts are silent.
They don't cause any damage.
And if your sighting comes with alien experiences, then you know.
It may be hard to tell.
But it's not impossible to tell.
I think the government stages more public sightings than the aliens do.
I think the aliens are more selective.
There are so many different shapes and sizes of alien crafts, that I would not be surprised by any sightings of them.
In the case of videos where craft were seen fighting, none of the alien races shoot at each other.
If such videos were true, I would sooner suspect the crafts to be human military, staging the personalities of the visiting races for the benefit of human confusion.
Men in Black
They are part of the propaganda campaign against the visiting races and against individual humans who have true contact with alien life.
The government Men in Black are still active, but the alien Men in Black are not.
I recommend my own site.
Otherwise get information firsthand by stable, credible individual humans who have personal contact.
Though, most humans who have personal contact are as confused about it as anybody else, naturally.
Also, many humans who claim to have personal contact, really do not.
There is only one place to learn truly about alien life and that is from the aliens.
The things that actually happen and how they happen are just so far beyond our understanding that any honest report can only be inaccurate and incomplete.
You shouldn't just go around believing things you hear without your own reason to, not even from me.
Just think for yourself.