NFL game predictions are based on guesses and statistics. There is still a large factor of luck that goes into the outcome of a sports contest at any level. NFL teams are very closely matched up, and the overall outcome of a single game can not be accurately predicted, even by experts.
NFL game predictions are notoriously inaccurate. Even those that pick games for a living get 50% of the games wrong, or no better than flipping a coin. In today's game, there is more parity, making the saying that any team can beat another in a given week more true than ever.
No, you cannot trust NFL game predictions because there are too many variables in a professional football game. Someone could be injured. Someone could be ejected. There is no telling what might happen, so no one knows for sure. One play could change the outcome, and experts cannot predict what will happen.
No, You cannot trust NFL game predictions. There is a term "Any Given Sunday" which means that any team can win on any day. It doesn't matter who the team is and what point in the season it is. Any NFL team can compete against any other team, and predictions can never be very accurate.