"All that the Father giveth me shall come to me; and him that cometh to me I will in no wise cast out" (John 6:37).
This promise of the Lord Jesus illustrates the beautiful yet paradoxical complementarily of the gospel. The Lord Jesus gladly receives all who voluntarily come to Him. "Come unto me, all ye that labor and are heavy laden, and I will give you rest" He says (Matthew 11:28). Yet those who come to Him do so because they have been given to Him by the Father.
Is this a contradiction? No, because both statements come from Christ. There are many Scriptures which teach that believers have been chosen by God, then drawn to Christ. On the other hand, there are many Scriptures which teach that one may freely accept or reject Christ and is responsible for his own decision. Yet the Scriptures themselves seem unaware that they pose a problem. For example, Peter preached on Pentecost saying, "Him, being delivered by the determinate counsel and foreknowledge of God, ye have taken, and by wicked hands have crucified and slain." And again, "The kings of the earth stood up, and the rulers were gathered together against the Lord . . . to do whatsoever thy hand and thy counsel determined before [i.e., `predestinated'] to be done" (Acts 2:23; 4:26,28). In these passages, divine predestination is joined with human decisions without a hint that these concepts conflict with each other. Once again, God's thoughts are higher than our thoughts.
Like the two sides of a coin, only one of which can be seen at a time, they are complementary truths, harmonious in the mind of God, but incapable of full comprehension by human minds. We can praise the Lord both for free salvation available to all who desire it and also for the comforting assurance that those who come have been "chosen . . . in Him" (Ephesians 1:4) before the world began. HMM