The New Covenant, which the Christian Church participates in, is an unconditional covenant of God's grace (His unmerited favor.)  It's fulfillment is dependant on God alone, therefore it cannot fail.  This is what He says He will do:

"I will put My law in their minds, and write it on their hearts; I will be their God, and they will be My people.  No longer will a man teach his neighbor, or a man his brother, saying, 'Know the LORD,' because they will all know Me, from the least of them to the greatest," declares the LORD.  "For I will forgive their wickedness and will remember their sins no more."1

The Christian Church, through Christ Jesus, also receives the blessing of Abraham.  We are blessed, of God, in all things. 2

Bible Reference:

1 (Jeremiah 31:33-34;  Hebrews 8:10-12)

2 (Genesis 24:1; Galatians 3:14; Ephesians 1:3)

Grace to you and peace from God our Father and the Lord Jesus Christ.