Isaiah 43:2

When you pass through the waters, I will be with you; And through the rivers, they shall not overflow you.  When you walk through the fire, you shall not be burned.  Nor shall the flame scorch you.

If the devil can make us feel alone, we will, but God being with us is not about feeling but faith.  The word reminds us that He will never leave us or forsake us and the harder we lean into to God the closer He comes to us.  We need to remind ourselves of this when we go through the valleys and wonder where God is?  He is standing right beside you, walking with you.