What is the specific meaning of "believe" in John 3:16? I would like to know the specific meaning of the word "believe" in John 3:16 when it says whosoever believes in Him shall not perish but have everlasting life.

Many people that I know say that they believe in Jesus but they are not Christians but they think that they are going to Heaven because they have a head knowledge or at least believe in a Creator God that created all things. Please tell me what the deeper meaning is of this incredible word. Is there a Hebrew or Greek meaning of this word that differs from what most people are thinking that this word means? The passage in John 3:16 sounds like if you just believe that there is a Jesus that this is all that you need to get to Heaven
To believe in Jesus is not the same as to believe about Him. To believe in Jesus means to trust Him, to entrust and commit ourselves to Him, to lay hold, to lean, and to rely upon Him. This includes believing that whatever He says is the truth.