In Isaiah 65, we find a long chapter describing God's judgment upon a people who were unwilling to respond his numerous calls. He promises a restoration, of course, but of those who heard the call of God and gave the desired response; the others receive judgment:
I will bring forth descendants from Jacob,
and from Judah inheritors of my mountains;
my chosen shall inherit it,
and my servants shall settle there.
Sharon shall become a pasture for flocks,
and the Valley of Achor a place for herds to lie down,
for my people who have sought me.
But you who forsake the LORD,
who forget my holy mountain,
who set a table for Fortune
and who fill cups of mixed wine for Destiny;
I will destine you to the sword,
and all of you shall bow down to the slaughter;
because, when I called, you did not answer,
when I spoke, you did not listen,
but you did what was evil in my sight,
and chose what I did not delight in (Isa 65.9-12).
It is important to see in the passage that the "chosen" of the LORD are those persons who responded favorably to God's call. There are no grounds for supposing that they are chosen a priori, before any independent response on their part to God's message. The chosen are "my people who have sought me," whereas the rejected are those who "did not answer" and "did not listen" when God spoke. The evidence for this is the fact that God's well-intentioned call goes out to all, and God desired that all respond favorably:
I was ready to be sought out by those who did not ask,
to be found by those who did not seek me.
I said, "Here I am, here I am,"
to a nation that did not call on my name (v. 1).
The LORD here presents himself as one favorably disposed to those who disregarded him, to all of disobedient Israel who had sinned against him. There is no basis in this passage for supposing that God might have chosen some to respond and some not. As far as the text is concerned, God's interest was that all respond favorably, but human beings act in some way independently of God's desires. Thus some of them responded favorably, and these are God's chosen, the ones whom he favors; others responded unfavorably, and these are promised a judgment.
What is a lesson to be gathered from this teaching? At least one important point is this: your choices have significance, and you must be very wary of choosing wrongly. You cannot sit back and cling to your election, as if this excuses your carelessness and unwillingness to put forth an effort. John the Baptist said to the Pharisees:
Bear fruits worthy of repentance. Do not begin to say to yourselves, 'We have Abraham as our ancestor'; for I tell you, God is able from these stones to raise up children to Abraham (Luke 3.8).
The point is: as far as election is concerned, God can always choose some other persons; God can always fulfill his promise to Abraham by other means than by you. If now you have the chance and the opportunity and the calling to be holy, then do not ignore it! Don't be easy on yourself; don't leave room for sin to take advantage of spiritual laziness.