2 Even Simon Magus once came to the Laver: he was baptized, but was not enlightened; and though he dipped his body in water, he enlightened not his heart with the Spirit: his body went down and came up, but his soul was not buried with Christ, nor raised with Him. Now I mention the statements of (men's) falls, that you may not fall: for these things happened to them by way of example, and they are written for the admonition of those who to this day draw near. Let none of you be found tempting His grace, lest any root of bitterness spring up and trouble you. Let none of you enter saying, Let us see what the faithful are doing: let me go in and see, that I may learn what is being done. Do you expect to see, and not expect to be seen? And thinkest thou, that whilst you are searching out what is going on, God is not searching your heart?
Source: Catechetical Lectures (New Advent)