What is Impossible for us -- He Has Already Taken Care of

"Then said Jesus again unto them, I go my way, and ye shall seek me, and shall die in your sins: whither I go, ye cannot come." (John 8:21)

Jesus spoke these words to the Pharisees, because they did not believe on Him.

You and I do believe on Him whom God the Father sent to die for us and give His life to us (John 3:16, 6: 29)

Jesus did say to His disciples that where He was going, they could not follow (John 13: 36), but that's because He gave us His Spirit, the Comforter (John 14: 26)

This same Spirit brings Christ to live in us (Colossians 1:27), and causes us to sit in heavenly places with Him (Ephesians 2: 6)

Because of the Holy Spirit who gives us His life, we can also claim with John:

"Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world." (1 John 4: 17)

We cannot come to Him because for every believer, Jesus has already come to us.