Yes, the problem is his football skills. He doesn't have the fundamentals to be a good NFL caliber quarterback.
Lots of top flight college QB's can't cut it in the NFL. That is rather normal.
Look xzins, an NFL franchise will hire virtually anyone if they think it would help them win. They are most certainly not anti-Christian. There are lots of Christians in the league and they manage to do just fine. Tebow's problem is he isn't good enough to be a starting NFL QB, and he is too outspoken and too much of a media draw to quietly sit in the background as a 2nd or 3rd stringer. As long as he remains in the spotlight, Tebow's going to always be a fan favorite amongst many Christians - and because of that teams will always see Tebow as a QB controversy waiting to happen.
Moreover, he is totally unique in my memory in this regard:He led what was a losing team to the playoffs, won his first playoff game, and then spent the following year totally unused.
In my mind, its impossible to say that Tebow is not an NFL caliber quarterback because the one time he had a chance to play, he succeeded all the way to the 2nd round of the post-season.
That is not true of Andy Dalton, RGBIII, and Andy Luck. Its not true of Tony Romo.
He's unique, longbow, in that he HAS SUCCEEDED as an NFL quarterback, and THEN he was no longer permitted to participate.