Am I without Jesus if I don't ask him into my heart?

Jesus cares about all people and His hand is always stretched out. He wants all people to simply trust in Him. We can begin by talking to Him in prayer. Express all the things you are grateful for and honestly and sincerely ask for His help in whatever you are struggling with. Live a life that acknowldeges Christ in it and seek to do good by following your God given conscience, striving to be better each day. This course will cause your faith or trust in Christ to grow until your faithfulness causes your faith to become unshakable and you will know that God will support you in all that you need. Then you can expect miracles.

I find nothing in the Bible where God commands us to “ask Jesus into your heart”.

He is our Creator, we are the created.  We are in rebellion to Him.  We need to fall to our knees and ask Him to mercifully and graciously receive us through our repentance of sin and belief in Him.

No.  You just need to trust Him as your Lord and Savior. 

Den is right. The only way to let Jesus in is to inhale a fine mist of him from the air or sucked out of a crackpipe.

In reality everyone is without Jesus, everyone is without the tooth fairy and everyone is without pixies on flying pigs.

Imagining something doesn't make it real.

Everyone is without Jesus, some people just don't know it.  :)