A man, for illustration, is sinfully tempted when he is solicited to perform a certain outward act, say to preach a sermon, by the craving of pride or ambition. This craving or inward lust after human applause is itself sin (John 5:44; 12:43; Rom. 1:25), and to be tempted by it is to be sinfully tempted. It is idolatry or creature worship in the heart. Even if he does not perform the outward act to which his pride or ambition tempted and urged him, he must repent of his wicked lust or pride of heart and obtain forgiveness for it. This is taught in Acts 8:21–22: “Your heart is not right in the sight of God. Repent, therefore, of this your wickedness [of heart], and pray God if peradventure the thought (epinoia) of your heart may be forgiven you.” Simon Magus’s particular lust was avarice; it was wickedness (kakia) and needed the exercise of mercy. Had it been an innocent desire, he might have continued to have it and needed not to repent of it.

Shedd, W. G. T. (2003). Dogmatic theology. (A. W. Gomes, Ed.) (3rd ed., p. 666). Phillipsburg, NJ: P & R Pub.