This advice comes from Elisabeth Elliot (again) in the form of an old poem:
“Many a questioning, many a fear,
Many a doubt, hath its quieting here.
Moment my moment, let down from Heaven,
Time, opportunity, guidance, are given.
Fear not tomorrows, Child of the King,
Trust them with Jesus, ‘DO THE NEXT THING.’
Do it immediately; do it with prayer;
Do it reliantly, casting all care;
Do it with reverence, tracing His Hand
Who placed it before thee with earnest command.
Stayed on Omnipotence, safe ’neath His wing,
Leave all resultings, ‘DO THE NEXT THING.’”