In order for man to accept Jesus, he must first hear about Jesus. It's not just an imaginary Jesus it's about what Jesus actually did and about what Jesus is actually doing now, from His exalted position in Heaven. Acceptance is receiving the the personality of Jesus into the heart. Acceptance is taking hold of the Spirit and character of Jesus. Acceptance is giving consent to the authority that Jesus has as Savior and Lord. So, what causes fallen man to accept Jesus? The Spirit of God.
The Spirit of God shows man what he really is (dirty, filthy, and without hope). The Spirit of God testifies Jesus and makes Him known. Man thus recognizes the fact that Jesus became a man just like you and I. Though the Spirit's ministration fallen men understand that Jesus suffered as a man and shed the blood of a man... so that sinful men could have a way to find forgiveness for their (dirty and rotten) sinful conduct. Outside of Jesus sinful men can never find personal forgiveness for their past sins. Only acceptance of Jesus Christ into the heart and soul can cleanse sinful men from the sin stains they live with in normal life...without Jesus.
Man's acceptance comes from a broken and contrite heart prodded by the Spirit of God. Sin (in a broken man) is only realized in light of the person and authority of Jesus Christ our Savior. Brokeness comes to the heart of fallen man from the convicting power of the Spirit of the Living God. Man's consciousness and awareness to Christ comes from hearing about Christ, as the Spirit of God ministers "truth and purity" to the human soul. Fallen man's acceptance comes from a realization of who Christ is. Acceptance (on a personal basis in submission) is man's recognition of Jesus with consent, brokeness, and understanding of what Jesus did on the cross at Calvary.
Man's acceptance of Christ "receives and takes hold" of forgiveness from all past sins. Acceptance allows man to realize that the guilt of sin is taken away, as result of the suffering and sacrifice of Jesus on the cross. Man's acceptance of Christ brings the changed moral character that only comes into the human soul by the power of God's Divine Grace. Acceptance looks to Jesus as the true and only source for holiness of heart and right living. Acceptance clings to Jesus for every need in life. The reason men accept Jesus is because they recognize His suffering for fallen man. Repentance turns fallen men to Jesus. Acceptance takes hold of the fact that Jesus is very God and Savior.
The witness of a man who has accepted Jesus for personal Salvation is an example and light for God. Not by choice, but by the Divine power of the Grace of God. Not in boast, but in humbleness of heart. Men who accept Jesus are changed men. Every sin is forgiven because they accepted Jesus as Savior. The heart is clean because they accepted Jesus as Savior. The testimony is strong for Jesus because men who accept Jesus, are mouthpieces for God. These holy men of God testify about Jesus. They tell the world about Jesus and behind every holy witness for Jesus, is the Spirit of holiness that raised Jesus from the Grave.
The reason men accept Jesus is because they hear about Jesus from people (like you and I) who were touched by Jesus. The Holy Spirit is behind these testimonies that minister truth. The Holy Spirit convicts the world of sin and unrighteousness and leads fallen men to brokenness. The Holy Spirit is moving now and also leading sinful men to an acceptance of Jesus. When sinful men "break" from realization of who Jesus is...they will accept Him as Lord and Savior and find forgiveness from all past sins and freedom from the guilt of sin. They will desire to do things pleasing in His sight because they have accepted Him, the True and only God. They will mind the Spirit of God because they have accepted Jesus as Lord as Savior.
ac·cept ....verb (used with object)
1. to take or receive (something offered); receive with approval or favor: to accept a present; to accept a proposal.
2. to agree or consent to;