But I thought the earth and Universe were only 6,000 years old?
The Earth and the Universe came into existence last Thursday. They merely had the appearance of age built in.
According to Bishop Ussher, maybe, but his timeline is not the standard accepted. It is derived from his studies, which were just as good as anybody else's, in his day. The only sure thing for a theist, is the old standby, "In the beginning, God created..."
He "spoke", and it came into existence... It's quite easily defended with articles like this, which defy accepted critical theory...
It's difficult for mere mortals like us to comprehend that God always was and always will be because we measure the short time between our birth and death in minutes, hours, days, weeks, months and years.
That short span is like an instant.