Well-meaning and surprisingly sweet, “Evan Almighty” offers the story of a modern Noah who follows God’s instructions to build an ark, and, along the way, finds a confidence and direction in life.

Director Tom Shadyac takes a character from his 2003 movie “Bruce Almighty” and places him in the middle of the action. Evan Baxter (Steve Carell) is a television news anchor who has just been elected to Congress and moves to Washington, D.C., with his wife and three sons. Once in office, Baxter does not have a clue how to deliver on his campaign promise to “Change the World,” and he appeals to God for help. His prayers are answered in a most unusual way, when God appears and tells him to prepare an ark in the manner of Noah. This course of action is difficult to explain to his family, much less his colleagues on Capitol Hill, especially when he takes on the appearance of the biblical Noah and is soon being followed by pairs of every imaginable species of animal, looking for their place on the boat.

After a promising setup, “Evan Almighty” fails to fully follow through. The film lacks focus and tries to be about too many things. At one point God instructs Evan that the biblical Noah story has always been misunderstood. Rather than being about God’s wrath, he says, it is really a “love story about believing in each other.” That kind of vague rationalization is an illustration of how the film never clearly defines the purpose of Evan’s task. Obviously, a showdown with the nefarious Congressman Long is in the offing, and Evan will, in some way, help the environment he has been obliviously abusing for so long, and his family will draw closer together, but all of these aims are presented in very scattered and none too subtle ways.

When Evan proudly drives his enormous new Hummer up to his brand new McMansion as trees are being clear-cut in the background, it is easy to predict that he will have some sort of an ecological epiphany before the end of the movie. In fact, the final lesson that Evan learns is that he should change the world, “one act of random kindness at a time.” This is a generous sentiment, but it seems at odds with the theatrical, showy story of Noah and the ark.

Although the film suffers from a lack of depth and, sometimes, logic, “Evan Almighty” has several redeeming qualities. Chiefly, it is an unapologetic story of a man who (albeit reluctantly) comes to believe in the power of prayer and gives his life over to God’s will, even if it means flying in the face of everything that is expected of him by his friends and his family. One of the most interesting exchanges between God and Evan comes when the man realizes that he ought to, in fact, must, do God’s will, and God intimates that that is often one of the hardest concepts that humans can grasp.

One of the running gags is that Evan must build the ark using ancient tools and technology, and he has to wear long, flowing robes. Hair and beard that grow at an alarming rate and turn white complete the look of the biblical Noah. Apart from the comedy inherent in his look and the panic it incites in his staff, it is never made clear why the physical transformation is necessary—especially when God is played by a dapper Morgan Freeman in perfectly modern white sweater and slacks. Perhaps the physical transformation, however, is necessary to mirror the internal transformation of the man.

Steve Carell is much more effective in Evan’s quieter moments than when he attempts the broad slapstick comedy sometimes required of the character. Carell portrays Evan as a man who is, at first, scared and lonely in spite of having many blessings and all appearance of confidence. As Evan goes on with his task and completes the ark, Carell clearly shows how much more confident he becomes. As his outward appearance becomes more eccentric, Evan quietly becomes more comfortable in his own skin, with the world around him, and with his family. Although he does not know what will happen to him, he is sure that he is doing the right thing.

Wanda Sykes is a comedic standout as Evan’s sharp-tongued assistant, Rita, the funniest character in the film. Freeman is his usual warm and wonderful self; his smoothly charismatic portrayal of God is kind and wise; likewise John Goodman capably plays the overpowering Congressman Long. These are the types of roles these actors could play in their sleep. The only off note in the cast is Lauren Graham as Evan’s wife, Joan. While she does a decent job of alternately showing support and frustration, she does not seem convincing as a would-be politician’s wife.

In short, “Evan Almighty” is a film that has a good heart, not to mention a few laughs. Although uneven, and sometimes frustrating for its lack of subtlety and reason, it offers a positive portrait of a man who tries against all odds to do the right thing.