God is always near us. Our old hymns book has a song like that. It says: God is always near me hearing what I say. Knowing all my thoughts and words. I couldn't remember the lines perfectly. This song has a great meaning. God is always near us. He knows what our thoughts are. He knows what our words are. He knows what what our actions are.
Our relationship with God is that of a father and child. We are the children of God. Can a father get so far away from the children to the extent that they would raise an alarm? I don't think so. God compared Himself to a sucking mother and asked if the tender care of a woman can cease towards the child she bare. That wouldn't be that possible because a caring mother can't forget her child. The Lord the concluded that even though a woman’s care can forget her child, He himself won't forget us.
God’s caring heart won't make Him forget us. It is our disobedience to His words that makes us turn away from Him. Just like a child who wouldn't want to obey the father’s instructions would keep himself far away from the father, that is how we have ran away from God because of our sinful ways.