Spiritual growth is a team sport.  While God could transform us all by Himself that's not how He chooses to work.  He wants us to work with Him.  Paul captures this dynamic well in 1 Corinthians:

1 Corinthians 3:6 I planted the seed, Apollos watered it, but God made it grow. 7 So neither he who plants nor he who waters is anything, but only God, who makes things grow. (NIV)

 Only God can make us grow, but our willingness to "plant" and "water" helps to determine what God is willing to do.  He won't transform us against our will.  He wants our willingness and our best effort.  Here are some resources available to you as you plant and water.