Pilot reported an airborne conflict with a glider.

Narrative

On a cross country flight from UNV-ZZZ there was a close encounter between my aircraft and an unknown glider. It occurred about 10 minutes after takeoff from UNV when I leveled out at 5;500 ft. I completed my cruise checklist and continued to scan for traffic. After about 30-45 seconds above and to the left of me I saw a glider that may have been just over 500 ft. from my aircraft. In order to keep more separation between myself and the glider I descended as I noted the glider was ascending. I also altered course to the right per right of way rules since we were both converging in a head on direction. While there was never an imminent threat of a MAC (Mid-Air Collision) for comfortability and for safety; I ensured to alter my current course. I was aware prior to the flight of heavy glider activity in the area as denoted on the VFR sectional chart along with checking surrounding airport directories for glider activity during my time for flight. Also prior to my flight I received a standard weather briefing and was not given any further information on glider traffic. I believe that the glider was able to get as close as it did because of its color (white) and it's lack of lighting. Along with high level cirrus cloud; the glider was hard to spot. In the future I would continue to be aware of possible glider activity and ask ATC for any possible reports of glider activity considering I already had flight following. I would also continue to use all available lighting on my aircraft to ensure my visibility. Finally; I learned from this experience how hard it is to see a glider or any vessel that is white when masked in a background of clouds. Differentiating the aircraft from this background can be difficult. However; now that I'm aware this optical illusion can occur; I'm more prepared to be able to identify this illusion and better scan for traffic in the future.