"Keep on"; "Cheer up"

These are two messages that have been sent to me lately. A great worker for God writing to me said: “A merchant in London, whom I know well, wrote me yesterday, urging me to keep on with the work. It appears that in one of my recent letters, I almost complained that the work was a little too heavy at my present age. I pass on to you his two words, ‘Keep on.’”
A day or two after another worker writing to me sent me the message, “Cheer up.” So “Keep on” and “Cheer up” was the spiritual tonic I needed, and I thanked God for the messages. We must “keep on” until God says “b”―we must “cheer up,” for in “due season we shall reap if we faint not,” and “we must not be weary in well doing.” And our Master says, “Let not your heart be troubled, ye believe in God, believe also in Me.”
There is no way out of sin to God, except through sacrifice. But the only sacrifice that could efficaciously deal with sin before God was that of Christ. W. K.