Sealed

I was intrigued by a scripture I read as a new believer decades ago. I was so baffled by such a suggestion and intrigue within me that I'm here today, submerged by everything it represents. It's found in 1 Timothy 4:1. It says that in later times, some will depart from the faith! My question was, why?
I thought I struck gold when I accepted Jesus, and I did! So, I wondered what that scripture meant and why it was given to the last remnant. But now that I found out why, I feel the need to warn God's people of what it means and why it was given to the last-century church...