There is no such thing as a non-denominational Christian. There are several groups that refer to themselves this way, but they all have quite specific beliefs, doctrine and practices (and a couple even condemn each other), but I digress.
How about something relevant to today? I assume if you are graduating you want to make a statement that will make a difference in the world.
From the Sermon on the Mount, you could try
Quote:
Blessed are the peacemakers, for they will be called sons of God.
(Matt 5)
or
Quote:
Love your enemies and pray for those who persecute you, that you may be sons of your Father in heaven. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. ... Be perfect, therefore, as your heavenly Father is perfect.
(Matt 5)
James is another one of my favorite books, I would consider something like this...
(this touches both wisdom (i.e. education) and the peace theme which is so important these days).
Quote:
Who is wise and understanding among you? Let him show it by his good life, by deeds done in the humility that comes from wisdom. ....
But the wisdom that comes from heaven is first of all pure; then peace-loving, considerate, submissive, full of mercy and good fruit, impartial and sincere.
Peacemakers who sow in peace raise a harvest of righteousness.
(Jas 3)
or this one which was always another one of my favorites. This is relevant for a religious person who has achieved an education.
Quote:
If anyone considers himself religious and yet does not keep a tight rein on his tongue, he deceives himself and his religion is worthless. Religion that God our Father accepts as pure and faultless is this: to look after orphans and widows in their distress and to keep oneself from being polluted by the world.
(Jas 1)