There is so much more to being saved than a prayer and Hebrews says it thoroughly.
Hebrews 10:35 Do not, therefore, fling away your fearless confidence, for it carries a great and glorious compensation of reward. 36 For you have need of steadfast patience and endurance, so that you may perform and fully accomplish the will of God, and thus receive and carry away [and enjoy to the full] what is promised. 37 For still a little while (a very little while), and the Coming One will come and He will not delay. 38 But the just shall live by faith [My righteous servant shall live by his conviction respecting man’s relationship to God and divine things, and holy fervor born of faith and conjoined with it]; and if he draws back and shrinks in fear, My soul has no delight or pleasure in him. 39 But our way is not that of those who draw back to eternal misery (perdition) and are utterly destroyed, but we are of those who believe [who cleave to and trust in and rely on God through Jesus Christ, the Messiah] and by faith preserve the soul.
There really is no pleasing God without faith, the just shall live by faith. It is impossible to please God without faith.
Hebrews 11:6 But without faith it is impossible to please and be satisfactory to Him. For whoever would come near to God must [necessarily] believe that God exists and that He is the rewarder of those who earnestly and diligently seek Him [out]. AMPC
There is only one way and that way is to press to believe in whatever circumstance we are in. What ever God promises it is our responsibility to believe Him, to rely and trust His Word no matter what the enemy comes against us with.
We already know the enemy will come, Jesus warned us as soon as we hear the Word Satan will come and try to take it from us (Mark 4:15). The Word is, God, and God is our faith therefore Satan will come and try to get us to doubt and to fear that what God said will not come to pass. So what God is saying is if you shrink in fear, if you let Satan convince you, if you let him steal God from you, you have flung away your confidence in God.
Whenever I get weary and have let Satan run his tires over me - I call out to God and He brings me back here to Hebrews. He reminds me that if I am in doubt, I am second guessing Him and believing the lie of the enemy instead of trusting Him. Trusting in and believing His promises will come to pass if I believe.
Galatians 6:9 And let us not lose heart and grow weary and faint in acting nobly and doing right, for in due time and at the appointed season we shall reap, if we do not loosen and relax our courage and faint. AMPC
Therefore the key is believe and not lose heart, don’t grow weary, keep living by the truth and you will reap. I can attest to this promise, His promises do come to pass but you just have to dig your heals in and be unmovable. Don’t let Satan talk you out of believing.
When we live by the Word and have God’s promises come to pass in our lives, we prove that God is good and that His ways are good and perfect. That is what God is asking us to do, He is asking that we live in agreement with Him so that we can prove His will is good and perfect, so that your unsaved loved ones can see God’s perfect will in your life and want God in their lives.
Romans 12:2 Do not be conformed to this world (this age), [fashioned after and adapted to its external, superficial customs], but be transformed (changed) by the [entire] renewal of your mind [by its new ideals and its new attitude], so that you may prove [for yourselves] what is the good and acceptable and perfect will of God, even the thing which is good and acceptable and perfect [in His sight for you].
Jesus said either we are for Him or against Him, therefore if we are for Him we will make it our quest to believe, proving in our lives the goodness of God (Matthew 12:30). Jesus said when we ask and it is given to us the Father is glorified, He is shown in our lives, we are representing Him attractively (John 15:8).