Things are not the same as when I was young. People don't leave the key under the mat anymore. You wouldn't feel very safe at night if everyone had a key to your front door. So now we have electronic key pads to lock our front doors and garages. Only our closest friends and family may likely have the code to get in. Everyone wants to feel safe in an uncertain world. Where no one really knows what may happen tomorrow but we all do our best to plan for a long life, safe and happy. We can do our best with locks and alarms to protect the lives of the ones we love but there are no guarantees in this life for tomorrow.
James 4:14-15 (Yet you do not know what your life will be like tomorrow. You are just a vapor that appears for a little while and then vanishes away. Instead, you ought to say, "If the Lord wills, we will live and also do this or that.")
Where should we look for our protection and security but to the Lord. We can have a promise of a happy tearless eternity. Or we can try to feel safe on our own in an uncertain world by locking our doors setting our alarms and arming ourselves. But in the end what do you have but death. 1 John 1:1-4 (What was from the beginning, what we have heard, what we have seen with our eyes, what we have looked at and touched with our hands, concerning the Word of Life and the life was manifested, and we have seen and testify and proclaim to you the eternal life, which was with the Father and was manifested to us what we have seen and heard we proclaim to you also, so that you too may have fellowship with us; and indeed our fellowship is with the Father, and with His Son Jesus Christ. These things we write, so that our joy may be made complete.)
We all know where our safety and joy and happiness can be made complete. It's in Jesus Christ and His saving blood and the grace of our God where eternal life is. The Word is where the door is and the key is under the mat. If you seek out the door to salvation, you can have the key and be welcomed home.