Most Altar Calls:
"You're in danger of hell. Repeat this prayer after me.."
"The plane is going down. Take this Jesus parachute.."
"Now that you've prayed that prayer here is what God wants you to do/here is how you can get involved in our church/etc."
"Now that you've got your Jesus parachute go fly the plane & save everyone else.."
Jesus' invitation to mankind was an invitation for Him to give us rest. Most altar calls stop offering you grace before the prayer is even over. "Here's the gift, now God wants you to get to work!" No time for rest. Jesus often told people he healed to not tell others what he had done. We need time to soak in the cure, to rest & be loved by Him, to learn His love for us by experiencing it. Scripture never calls us "God's missionaries" it calls us "God's children." Children aren't forced to work 3 seconds after they are born, likewise God's children as they are reborn are not commissioned by God to work but invited by Him to rest.
Jesus also described himself as "gentle & humble." For many God is rarely seen as gentle. Someone who needs to forgive all the time because he is perpetually offended & angry is not gentle. Even rarer & in opposition to all religion is a God who is humble. God is pictured as doing everything "for His own glory" & we are supposed to do likewise. Jesus who perfectly represents Our Father is humble, humble in His heart. God's mindset is not works based, sin based, or ego based. Yet He has been taught to be all of those things to the uttermost where almost all He thinks about is people's works & sins & how much he should be praised.
So if we view God as ungentle & unhumble we will not be able to rest. How could anyone rest thinking there is a harsh conceited egomaniac "lording" over them 24/7? If you are put off by me opposing the idea that the purpose of everything is to bring God glory consider that "Love is not self-seeking" & "God is love."
Here are some things you cannot rest with:
The need to be repeatedly forgiven
The call to constantly work or grow or improve or act "right"
The idea that sin has any power over you
The pressure to "get out of your comfort zone"
The command to be holy or perfect
The pressure or responsibility to change or save or evangelize the world
The idea that you have to constantly gain your Father's approval