Opposite words for gap:
continuation, completeness, continuity, run, stretch, continuum, fullness, progression, procession.
Usage samples:
  1. There's a gap in my life.
    "The Song of Songs", Hermann Sudermann.
  2. The light shone on swift black water, and a wind rushed through the gap that nearly blew the torch out.
    "King--of the Khyber Rifles", Talbot Mundy.
  3. Real wages, which had been falling, reached their low point and the gap between the poor and others widened.
    "Our Legal Heritage, 4th Ed.", S. A. Reilly.
  4. When I am dead, the sunset light Will fill the gap upon the height In summer time, but on the plain Sink down as winter comes again And none who sees the evening red Will know I loved it, who am dead.
    "The Spinners", Eden Phillpotts.