Good question, and it’s one I think every Christian has probably wondered at some point in their spiritual journey.
Here’s the thing: Salvation is a choice. We choose God, or we choose Satan. In Matthew 12:30, Jesus says that whoever is not with him is against Him.
Our Lord is a loving God. He provides the path to Salvation for each and every one of us, and His love for us is unfathomable. He poured out His life for us on the Cross at Calvary to show just how much he longs for us to be with Him in heaven. His love is unfailing.
That being said, God doesn’t send us to hell.
It’s something we choose.
And yes, it’s real.
This article explains it really well: http://www.catholic.com/magazine/articles/hell-yes-part-i
Countless times in Scripture Christ heals people overcome by demons, and Satan himself tempts Christ. Thus, Satan is very real. And it is one of his most powerful weapons against us to cause us to believe that he doesn’t actually exist.
Hope this makes sense, and keep sending in questions if this isn’t clear or something doesn’t seem accurate.
Peace in Christ,