Hebrews 3:7-11 (ESV)
Therefore, as the Holy Spirit says,
“Today, if you hear his voice,
 do not harden your hearts as in the rebellion,
on the day of testing in the wilderness,
 where your fathers put me to the test
and saw my works
 for forty years.
Therefore I was provoked with that generation,
and said, ‘They always go astray in their heart;
they have not known my ways.’
 As I swore in my wrath,
‘They shall not enter my rest.’ “
Verse 11 is truly frightening. The reason the Israelites did not enter the Promised Land was because God swore an oath that they would not. He had become so angry at them for the intransigence of their sin that they sinned beyond the point where God was willing to even allow them to return to Him. Hope for repentance was gone. This is consistent with the testimony of Romans 1 as well.
The God of whom the writer to the Hebrews refers is our God. He still gets angry at sin. He still holds His hands out to a stubborn and rebellious people. He still grants untold numbers of opportunities for people to turn from sin and turn to Him. And He still makes oaths to destroy those who are so intransigent in their sins that they will not repent.
People who have a smattering of Christian teaching often presume upon the mercy of God and assume that it will always be available to them. It will not. They plan to come to God some day and get their lives straightened out not realizing that God may close the door on the opportunity tomorrow.
It is legitimate to wonder if the culture we live in has come to the point when God has sworn in His wrath that people will not be saved. We do not know for sure and until the doors of the Bible believing church are finally shut by Him we will continue to declare the Gospel to those whom God puts in our path.
People need to hear this. Even though they do not want to they need to. They need to know that their sins condemn them and that if they do not turn to God a day may come when they will not be able to. It is a fearful thing to trifle with the God of all creation. It is a horrible neglect of the Scriptures and of our calling to downplay the wrath of God. It is a horrible thing to imply by our neglect, that God is not going to pour out His wrath on the ungodly. He will. He is. And we who know Christ need to be warning people about it.