From the second commandment, it is obvious that God expressly forbids the making of any representation of Him. Any such picture or statue is automatically a lie because, other than knowing that we are in His physical image as to form and shape, everything else that He is cannot be expressed in a mere physical depiction.
John 1:18 confirms this truth: "No one has seen God at any time. The only begotten Son, who is in the bosom of the Father, He has declared Him." God is unique; nothing compares with Him. There is no point of contact, no physical reference, to which a human being can compare Him, revealing the absolute folly of image-making. Even Jesus' declarations regarding God are never about what He looks like, but are all about His authority, position, purpose, character, and attributes.
However, knowing the importance of His purpose to our lives, should we not strive to learn what He is like? God does not want us concerned about what He looks like, for that puts the emphasis in the wrong area. He gives us enough information for us to know that He looks like a man—and that is enough.
However, He greatly desires that we know what He is. The entire Bible reveals His mind, character, attributes, offices, power, will, promises, plan, and relationship to us. The third commandment deals with these areas of study and application because they deeply affect the quality of our response to Him.