Believing about Jesus is not the same as believing in Him.  A Jewish person, or a Moslem, may believe about Moses or Muhammad, in a manner that leads, but certainly not in them in the way that saves. No matter how glorious your heroes, your belief about them will never save you from your sins. 

When in the heat of passion, you said to your beloved, “I love you,” in that moment, you become emotionally bonded for better or for worse.  A part of you became them, and a little part of them came into you. To that person you gave your first earthly loyalty. Unfortunately, it can never be the saving love you are seeking, only heavenly bonding can do that. 

If Jesus were here today, you could indeed believe into his divinity. Part of him would come into you and your old sin self would dissolve into Him.  You would indeed be born-again and saved.  

"So where is Jesus now that He might open your heart to believe into Him and that he may come into you?"

Depending upon how you believe, the Jesus experience can be a believing soul saving experience or an enslaving devotion. So where is Jesus now that He might open your heart to believe into Him and that he may come into you? 

Sadly, we know Him mostly through books, ceremonies and rituals. In the same way you attach yourself in a relationship to an unsaved mortal being, what you mostly get from church are those same uplifting emotions and glorifying religious feelings that masquerade as a genuine religious experience.  In the conversion excitement, the church, rather than Jesus comes into you. Something is missing.