The spiritual, moral and substantive difference between God and man requires that there be a mediator who bridges the gap between us.
"Wherefore, holy brethren, partakers of the heavenly calling, consider the Apostle and High Priest of our profession, Christ Jesus" (Hebrews 3:1).
The God who is man and the man who is God spans the vast gulf between Divinity and humanity, both in Himself, and for the benefit of the parties who seemingly could never unite. "Great is the mystery of godliness: God was manifest in the flesh" (II Timothy 3:16). Apart from such gracious condescension, "never the twain shall meet," as it were. And never will we have any other hope and assurance for relationship with God save in the high priestly and mediatorial work of the Lord Jesus Christ. "There is one mediator between God and men, the man Christ Jesus" (I Timothy 2:5).
When the wrath of God seemingly must be poured forth upon a wayward humanity, the Lord Jesus enters the picture to vicariously bear such wrath for us. "For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God" (I Peter 3:18). When man has no interest in God, the Lord Jesus reveals the Divine heart and sends forth the Holy Spirit to convince and convict us of our need for the Divine. "And I, if I be lifted up from the earth, will draw all men unto Me" (John 12:32). Christ alone provides hope forevermore that God and man shall unite in a permanent union of love whereby both hearts rejoice in each other despite seemingly irreconcilable issues.
Never have we so failingly sinned that we cannot come to God, so long as we come by way of the person and work of Christ on our behalf. And never have we so faithfully served that we can come to God in any other way than the person and work of Christ on our behalf. He is our High Priest, our mediator, our bond of peace, and the One who "ever liveth to make intercession for us" (Hebrews 7:25). Yes, in the Lord Jesus, God and man unite in the miracle of Christ's own personhood, and in the mercy of living relationship between "twain" who seemingly should "never shall meet," but who find in Christ a union of loving devotion that endures forever - and in this moment.
"Seeing then that we have a great High Priest, that is passed into the heavens, Jesus the Son of God, let us hold fast our profession. For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need."