Psalm 28:5 says, in describing wicked men, “Because they do not regard the works of the LORD, nor the operation of his hands, he shall destroy them and not build them up.” The significance of this verse can easily be missed if we do not take the time to consider exactly what it is saying about men and women who do not know God. In v.3-4 the psalmist has already described these people as “workers of iniquity,” with evil “in their hearts,” and whose endeavors are “wicked.” Clearly, he does not have a high view of their moral status, but it is what he says in v.5 that really gets to the root of their problem, and it is this statement which is profoundly controversial in 21st century Western society.
Yes, their deeds are evil and deserving of unpitying judgment, and they are hypocrites who speak peaceably to their neighbor while plotting mischief in their hearts, but the real reason that men and women are damned by God is that they refuse to believe on him. They do not regard his works or the business of his hands, and what this means is they do not give attention to the things that God has done or is doing. They are preoccupied with fulfilling their selfish desires, so that they give no thought whatsoever to the things of the Lord. In other words, no one disbelieves in God because of a lack of evidence but because of a refusal to consider the evidence. The works of God’s hands are plain, yet men and women continue to act as though they were not, defying the “law of spiritual gravity,” as Arnold Anderson puts it.
Charles Spurgeon explains it this way: “God works in creation – nature teems with proofs of his wisdom and goodness, yet purblind atheists refuse to see him: he works in providence, ruling and overruling, and his hand is very manifest in human history, yet the infidel will not discern him: he works in grace – remarkable conversions are still met on all hands, yet the ungodly refuse to see the operations of the Lord.” 
As we see repeatedly taught in Scripture, man’s problem is not a lack of evidence concerning the existence and nature of God but a refusal to even consider the proof that practically screams it in his face. And the result of his denial is that he will be torn down like a decaying house with a cracked foundation and a sagging roof.
If you remain aloof from Christianity, unable to commit yourself to the Lord Jesus Christ, it is not that God has failed to prove his existence, but that you have chosen to reject the Lord who has lovingly and graciously reached down to show himself to you. He condescends to teach, yet you refuse to learn. But the very fact that he has made himself known by his works is evidence of his love. You may still believe on him and be built up instead of being torn down. Give attention to his works and the operation of his hands, that you may come to know the Almighty, the Savior of his people.