Even if you don’t achieve reconciliation with yourself and forgiveness of yourself, even then he will forgive you for your intention and for your great suffering… for there are neither words nor thought in human language to express all the ways and means of the Lamb, “until his ways are made manifest14 to us”. Who can embrace him, the unembraceable, who can understand all of him, the infinite!’
I don't agree with this. There is no sin greater than the forgiveness of Christ but you do have to accept the forgiveness. That is what repentance is.
I don't take Tikhon a speaker of Dostoyevsky's beliefs. (Similar to the first monk we see in this book. All the monks we see in Demons seem to be a criticism on monks who lose their way. It's characteristic for even the monks of this novel to be a bit skewed.) Not even Father Zosimov (TBK) is, though he is definitely the closest. Because men of faith are still men and are flawed, especially this one (Tikhon) of flawed faith.