Facing the Giants

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Grant Taylor (Alex Kendrick) is the head coach for the Shiloh Eagles football team at Shiloh Christian Academy, and has yet to post a winning record in his six-year tenure. After his seventh season begins, he learns that his Running Back, tired of losing, has transferred to a rival school as he moved in with his dad in that school district. Grant is frustrated as this is the third time he has spent developing key players but having them transfer schools in their senior year. Consequently the team is discouraged and write the season off since he was the one who scored a third of their points last year. Not surprisingly, the discouraged Eagles get shutout 23-0 in their first game.
Larry Childers, who is confined to a wheelchair, and his son David have recently moved from Athens, GA where David is entering his junior year at Shiloh. David is a soccer player but Shiloh does not have a soccer program so Larry encourages him to try out for the football team as a kicker despite David's reservations. David is nervous due to his small stature and lack of experience in football, but his dad tells him not to be afraid of failure. After try-outs, the coaching staff see promise in him and he makes the team. As the day ends, Grant notices a player on his team named Matt disobeying his father's orders to come straight home, instead heading off to hang out with his friends.
In the next game against Dewey County (a game which the Eagles are favored to win), the team totally falls apart and loses 21-7 frustrating Grant to the point where he holds a closed door team meeting and berates the team for giving the game away due to their poor offense as well as certain players for missing practice as they had detention for slacking off in class. At the end of the meeting, "If we're not here to win football games then why are we here?!" Later that night when David discusses the game with his dad, he agreed with the coach and was glad to not have played that game and get berated, but his dad again brings up the point that he still has fear in him due to excuses.
After locking up the school for the night, Grant overhears several parents of the football team trying to convince Dan Ryker, the principal to fire Grant as a coach and find someone else. Grant also notices Brady Owens, one of his assistant coaches, present. This is not the only problem Grant is facing. Outside of football, his car is breaking down and he cannot afford to get another one, some things in his home are not working properly, and he discovers that he is the reason that his wife Brooke (Shannen Fields) cannot become pregnant. With all these issues (giants) that Grant is facing, he breaks down with Brooke. the following morning, he begins asking God for help and God begins to change his perspective on life and his approach to the team.
The following game, Grant decides to allow David to kick. David fails, and because of this, they lose the game, making their season 0-3. After the game, David reveals that he already figured that he would fail, but Larry tells him that the more he accepts defeat, the more likely he is to receive it. Meanwhile, one of the school preachers, Mr. Bridges approaches Grant and tells him that the Lord isn't done with him, and encourages him to have faith. Grant returns home and creates a new team philosophy.
During the next team meeting, Grant offers anyone $10 if they could guess the team who won the sports championship 10 years ago, then 5 years ago. When nobody could come up with the correct answer, he tells the players that trophies and other material awards as well as personal recognitions, only last for a short while. He then challenges the players when it comes to their future in life and their true purpose for playing football as well as focusing on praising God, no matter what the result.
During practice in preparation for their next game against Westview, Grant calls out one of his influential players, Brock, to do the death crawl (crawling across the football field with the knees and elbows off the ground and with another lighter player on top) after hearing him write off their next game as a loss. Grant tells Brock to crawl to the 50 yard line but makes him do it blindfolded for the purpose of maximizing his potential. As Brock is struggling, Grant continually encourages him not to quit along the way and Brock ends up crawling all the way to the end zone. Grant sees Brock as an emerging leader and tells him that the team will sink or swim with his attitude. Before heading home, Grant personally rebukes Matt to respect his father.
Inspired by this, the Eagles come together as a team and defeat their opponent. Under God's guidance and provision, things begin to take a turn for the better as the players take their studies in school seriously after earlier boasting about their low grades. There is a revival at the school as students start openly praying and sharing their burdens with each other. As a result, the Eagles begin a winning streak resulting in a post season appearance and a pay raise for Grant, Matt reconciles with his dad and they secretly buy Grant a brand new pickup.
During the post season game against Princeton Heights, the Eagles put up a valiant effort but come up short. Learning from Grant's previous lessons, they praise God despite the loss. As the team begins packing up their gear and calling it a season, coach Grant receives a phone call. Later, he calls an impromptu meeting with the team and informs them that Princeton Heights has been disqualified for cheating when they played two ineligible 19 year olds during the game. As a result, the Eagles have advanced to the quarterfinals which eventually leads to the state championship game against the three-time defending champion Richland Giants.
Even though the Eagles have only a third as many players as the Giants, the Eagles hold their own through a series of trick plays, including creating a "Stone Wall". Richland Coach Bobby Lee Duke gets cocky and refuses to go for field goals at all. The Eagles use their Stone Wall defense and stop 4 downs at the touchdown line, the last of which end in a fumble towards the 49-yard line. However, with just a few seconds left, Grant has David kick a field, despite the fact that he had never kicked more than a 39-yarder before. Grant encourages David to believe in God, and David kicks the field goal, winning the game 24-23.
In the locker room after the game, Grant and the team praise God and realize that nothing is impossible when God is on their side. At home, Grant's prayers for children are also answered as Brooke reveals that she is pregnant, something they had been trying to accomplish for four years. Two years later, Grant is shown to be playing with his two-year old son, while a pregnant Brooke watches. It is also shown on a shelf that a second state championship victory happened, with a quote in the middle; "With God, all things are possible", Matthew 19:26

Question: Who challenges the players?
Answer: Grant; Grant