All are asked to do something that they view as wrong, evil or inappropriate and will seem to be inconsistent with the Lord's mercy, righteousness and perfection. The request will unmistakably come from Him. You cannot evade the request because you doubt He is asking. You will clearly know it is Him who asks, and that to all your understanding it will be wrong to do. You must do it anyway.
All are able to develop the faith to lay hold on eternal life only because they have been led by Him through this process. When they have the faith sufficient to lay hold on these things, the Lord will declare to them by His own voice, that they have been begotten of Him and have a place with Him in eternity.