Creation, for instance. There's the physical universe. Time, space, matter. Each of those consist of three, time consists of past, present, and future. Space consists of height, depth, and breadth.
Matter consists of solids, gas, and liquid.
Then there's mankind. Mankind consists of body, soul, and spirit. Man includes man, woman, and child. The Christian life consists of faith, hope, and love. Knowing, brethren beloved, your election of God.