This scripture doesn’t say Abraham believed in God; it says Abraham believed God.  Abraham actively believed God would fulfill God’s promises in and through him.  His belief was credited to him as righteousness, meaning he entered a gracious, covenantal relationship with God when he believed God.  Similarly, when we believe God – praying His Word, asking Him for His will – we develop a deep friendship with Him and trust Him in everything!  Ask God to be your true friend and believe He will fulfill His promises in you for the glory of His kingdom!