What is Ivan's attitude towards religion in "The Death of Ivan Ilyich"?

Religion seems to play little role in the life of Ivan Illyich. It is clear that he believes in God or some sort of higher existence, and yet he only really confronts God when it is clear that he is dying and there is no hope for him. He only takes communion in Chapter 11 at his wife's behest, and does experience some relief from this religious ceremony:

When the priest came and heard his confession, Ivan Illyich was softened and seemed to feel a relief from his doubts and consequently from his sufferings, and for a moment there ame a ray of hope. He again began to think of the vermiform appendix and the possibility of correcting it. He received the sacrament with tears in his eyes.

However, this relief is short lived, as he is again confronted with the falsity of his wife and all that she represents and is forced to face the inevitability of his own death. Thus, the little mention that religion is given supports the deception and the "lie" that forces Ivan Illyich's family to continue as if nothing was happening and to try to ignore the fact of their father's death. It is interesting that in his final moments there is no mention of God, and the release that Ivan Illyich finds in the light that he sees instead of death does not come from religion but from the affection and love of his son.

In The Death of Ivan Ilyich, is Ivan a religious man and how do his goals, attitude, and values change?

No, Ivan is not a religious man, but upon his death he has an epiphany which transforms him. He lived a normal life, trying to follow the middle-class expectations of success.  He really didn't love his wife, and his values were materialistic, exemplified by him remodeling his house to look exactly like the homes of others in his social position. His relations with people have the semblance of friendliness, but he never develops any close or deep relationships.Only on his deathbed does he question this, as he begins to think about his family more than himself, resolving to act "so as not to hurt” his family . . . .to release them and free himself.”This gives him joy and peace, which Tolstoy links to Ivan’s new commitment to love and pity.  Here, then, we arrive at the major religious theme of this story:the discovery of God through the discovery of a selfless love of others.  It is significant that Ivan’s new consciousness emerges after a final period of “three whole days, during which time did not exist for him.”  Some critics think that this time suggests the period between Christ’s death and resurrection. Critics also suggest that Ivan's "fall" parallels Adam and Eve's fall in that both are fortunate because they ultimately allow the individuals to achieve a state of grace--a deeper knowledge not previously accessible.