Romans 10:6-13
Christ's justification of a sinner becomes personal “by faith” (Romans 5:1). Faith requires our acceptance of the substitutionary sacrifice Christ performed on our behalf to accomplish what we are unable to achieve on our own—reconciliation with God. It is not inherent, but the result of our individual belief—our acceptance and appropriate response to the calling we receive from the Father (Romans 4; 3:22; 10:4, 9-11; Ephesians 1:13, 19; Acts 16:31).
This faith is not some impersonal, abstract phenomenon. Instead, it is a concrete, spiritual manifestation of the will of God, given by God personally and individually through His Son and must also be received personally and individually by the one being reconciled to Him (I Peter 1:7). Nor is it faith in anyone else, but only in Jesus Christ, personally. Romans 5:1 says, “Therefore, being justified by faith, we have peace with God through our Lord Jesus Christ” (emphasis ours). Faith in anyone else will not declare a person justified. Our faith must be in the One who bore our sin in His own body, the One in whom the fullness of the divine nature dwelt (Colossians 2:9; Romans 8:3; Galatians 1:4; I Peter 3:18; I John 1:9; 4:10; Revelation 1:5).
Martin G. Collins
Are You Justified?

God alone initiates a calling, for man cannot find God on his own. The world, including most of physical Israel, remains consigned to unbelief until later in God's plan, even though most modern Israelites would claim they know God or believe in Him. God generally introduces people to Himself, though they may suppose they initiated the contact by calling on the name of the Lord. Men must first hear of Him through a preacher, one whom God has sent rather than one who is self-proclaimed.