Psalm 107.2 declares, let those delivered by the LORD speak out, those whom He delivered from the power of the enemy.
Who is the enemy? The enemy of all humanity? Death.
Only one God promises deliverance from death to ALL who humble themselves and follow Him. Only one God proved His ability to deliver on His promise by Himself rising from the dead after men were convinced of their killing Him on a cross.
Buddha did not rise from the dead nor does He promise eternity as a guarantee for following Him. Mohammad did not rise from the dead and neither does he promise eternal life to everyone who follows him.
Jesus alone promises eternal life because He claims to be the Creator and Author of Life. God became Man so that man could live with God forever. What better way for God to demonstrate His love for us than by becoming one of us? What better way could God prove His promise than by suffering death like all people must suffer only to rise from the dead guaranteeing to all who follow Him that they too will rise from the dead?
Jesus appeared to more than 500 before leaving this earth and returning to heaven where even now He intercedes on our behalf. Furthermore He has not left us as orphans but has instead given His Spirit to live within all those who love Him so that they can know unequivocally that they are indeed children of God.
So what should be our response toward the only true God Who has loved us so greatly and promises us what we all really want, life forever? Tell others this good news. God in Jesus the Savior does not want to be kept a secret. He left earth physically so that we would prove successively that God loves us and will lead us to life after death if we will but follow Him.
We prove this claim by our own commitment to the claim as evidenced by our obedience to God and our love for one another. As God loved us so we love one another. As God the Man perfectly obeyed the Word of God so too those who follow Him prove their love for Him by their obedience to Him as recorded in the Scriptures.
His command is that we give witness to His reality, to His work and to His promised future. The people of God have been delivered from the enemy of their souls so must cry out to others that they too might be delivered.