John 3: 16 For God so greatly loved and dearly prized the world that He [even] gave up His only begotten ([unique) Son, so that whoever believes in (trusts in, clings to, relies on) Him shall not perish (come to destruction, be lost) but have eternal (everlasting) life. AMPC
Believing in Jesus is more than just a prayer saying we believe. Believing in Jesus is agreeing with Him by living His way in His Kingdom right here and now on the earth.
When we make it our quest to know Jesus, to believe, trust and rely on Him now, then on that day when we leave here we will move in with that One we believe, the One we know.
God said to me one day. Many think they want to move in with Me one day, but right here and now they don’t agree with Me, or even have time for Me, yet still they think they want to move in with Me when they leave here.
So you see it isn’t just a prayer but a commitment to know Him and be in agreement with Him.