No one is safe until they are in Heaven. Unless Jesus tell you Himself that you are saved, then you honestly don’t know. So if someone asks you if you are saved, tell Him, “He hasn’t told me yet.” Then ask the guy if He knows Jesus’ phone number so you can call and ask Him.
The website you provided is just weird. I don’t understand why it was even put up because it is badly written, does not provide accurate information. I suggest that you ignore the site whose writers have a good reputation. A few good authors, Lee Strobel, and Peter Kreft are good beginners.
I agree with the above statement to a certain point because in the end no one is ever totally certain because it is God who saves us from our sins and not man. That said, when someone asks you if you have been saved, they are basically asking you if God is your God, the Christian God, the one of abraham and Isaac? They are asking if Jesus is your personal saviour, if he is your christ. As Catholics it becomes easy to take both granted and by saying that they are, you are reaffirming what you believe. In other words Jesus becomes your saviour and not the easter bunny. When in doubt, there are many prayers that in essence all mean same thing which invite God and Jesus to be part of one’s heart forever. For example:
A long version
Dear Heavenly Father, You have called me to Yourself in the name of Your dear Son Jesus (Yeshua). I realize that Jesus is the only Way, the Truth, and the Life; and is the only Mediator between You and man.
I acknowledge to You that I am a sinner. I believe that Your only begotten Son Jesus Christ shed His precious blood on the cross, died for my sins, and rose again on the third day. I am truly sorry for the deeds which I have committed against
You, and therefore, I am willing to repent (turn away from my sins). Have mercy on me, a sinner. Cleanse me, and forgive me of my sins as I forgive anyone who has ever sinned against me.
I truly desire to serve You, Lord Jesus. Starting from now, I pray that You would help me to hear Your still small voice.
Lord, I desire to be led by Your Holy Spirit so I can faithfully follow You and obey all
of Your commandments. I ask You for the strength to love You more than anything else so I won’t fall back into my old ways.
I also ask You to bring genuine believers into my life who will encourage me to live for You and help me stay accountable.
Jesus, I am truly grateful for Your grace which has led me to repentance and has saved me from my sins. By the indwelling of Your Holy Spirit, I now have the power to overcome all sin which before so easily entangled me. Lord Jesus, please
transform my life so that I may bring glory and honor to You alone and not to myself.
Right now I confess Jesus as the Lord of my life. With my heart, I believe that God the Father raised His Son Jesus from the dead. This very moment I acknowledge that Jesus Christ (Messiah Yeshua) is my Savior and according to His Word, right
now I am born again. Thank You, Jesus,
for coming into my life and hearing my prayer. I ask all of this in the name of my Lord and Savior, Jesus Christ. Amen."
Or
short version
“Father, I know that I have broken your laws and my sins have separated me from you. I am truly sorry, and now I want to turn away from my past sinful life toward you. Please forgive me, and help me avoid sinning again. I believe that your son, Jesus Christ died for my sins, was resurrected from the dead, is alive, and hears my prayer. I invite Jesus to become the Lord of my life, to rule and reign in my heart from this day forward. Please send your Holy Spirit to help me obey You, and to do Your will for the rest of my life. In Jesus’ name I pray, Amen.”
I believe this type of prayer when prayed wholeheartedly can be life changing and has a place inside the Catholic denomination. It certainly affected my life in a positive way. They can help dedicate one’s life to God, and renew one’s connection to God over time. It’s a prayer that you can say as many times as the spirit leads.