“Der” Words
The definite article has the fullest set of endings of any nominal or adjectival form. A few related words take the same set of endings as the definite article; they include the following:
The demonstrative adjective “this, that, these;” which has the same form as der, das, die except that it is accented in speech. The relative pronoun “who, which” is also der, das, die, except for the forms dessen (g.s m&n) and deren (g.s.f; g.pl) and denen (dat pl).
Other “der” words include”
dieser, dieses, diese this
jeder, jedes, jede each, every
jener, jenes, jene that
mancher, manches, manche many (a)
solcher, solches, solche such
welcher, welches, welche which
“Ein Words”
The words that take the same endings as the indefinite article include the possessive pronouns mein, dein, sein, ihr, unser, euer, and Ihr; and also kein.
The declension of the indefinite article ein and the possessive mein (in order across Masc, Neut, Fem Sg; then the plural of mein in all genders; ein, of course, has no plural)
Nom ein ein eine —–
Nom mein mein meine meine
Gen eines eines einer —-
Gen meines meines meiner meiner
Dat einem einem einer —-
Dat meinem meinem meiner meinen
Acc einen ein eine —-
Acc meinen mein meine meine
Theological German/Theologisches Deutsch 
You’re website is very inspirational to me.
Well thank you Tori–I’m glad you can get inspired by “der” and “ein” words :)-
I have always like the phrase, “alles Liebe, alles Gute, und viel Schönes!”
And, of course, the old standby, “Aller Anfang ist schwer.”