Only if you reject Scripture on the basis of it being incompatible with evolution. For example, if you hold that:
A) Adam was formed from the dust.
B) Adam’s body was evolved from non-human creatures
You are holding two contradictory positions, but you are not explicitly denying the Scriptural truth. However, once you say:
“Because I know that B is true, I no longer believe A”
Then I think you are risking falling into sin, because it should be the opposite. Because we know Scripture is true, all things that contradict Scripture must be false. Now, most people don’t do that. They split the difference and say:
“Because I know B is true, I therefore must believe that A is an allegorical truth and not literal.”
As far as that goes… I cannot say. Is it sinful? I believe that most of the Church Fathers would probably say that it is, because we should not deny the literal meaning of the Scripture unless it is inconsistent with reason. However, I do think it would be less sinful (assuming it is sinful which I cannot say with authority) than to outright deny the Scripture entirely.
Let’s look at another example and see how it plays:
“Because I know that human biology requires both male and female parents, the “virgin” conception of Jesus must not be literal but is actually an allegorical truth.”
Would you say that is a sinful belief?