Three times Peter denied Jesus after He had been arrested, was being unjustly accused, and being put on trial. Peter behaved cowardly and afraid for his life.
As passionate and fiery as Peter was, much of what he did was impulsive. This personality trait was a grief to Peter more than once! Fiery, impulsive, people can often regret that quality about their self, for it leads to embarrassment and undesired outcomes and consequences.
The truth was, Peter did love Jesus. The problem was that Peter was incredibly human and weak. Later, and as a result of this account, he would change - all because of the love of Jesus.
Mark 14:66-72 relates the account of Peter's betrayal of Jesus. It says: And while Peter was below in the courtyard, one of the slave women of the high priest came, and seeing Peter warming himself, she looked at him and said, “You were with Jesus the Nazarene as well.” But he denied it, saying, “I neither know nor understand what you are talking about.” And he went out onto the porch. The slave woman saw him, and began once more to say to the bystanders, “This man is one of them!” But again he denied it. And after a little while the bystanders were again saying to Peter, “You really are one of them, for you are a Galilean as well.” But he began to curse himself and to swear, “I do not know this Man of whom you speak!” And immediately a rooster crowed a second time. And Peter remembered how Jesus had made the remark to him, “Before a rooster crows twice, you will deny Me three times.” And he hurried on and began to weep.
Following Jesus' resurrection, He met with the Disciples and cooked them breakfast. It was at this time Jesus gave Peter a wonderful and healing gift of reconciliation. John 21:15-17 says: Now when they had finished breakfast, Jesus said to Simon Peter, “Simon, son of John, do you love Me more than these?” He said to Him, “Yes, Lord; You know that I love You.” He said to him, “Tend My lambs.” He said to him again, a second time, “Simon, son of John, do you love Me?” He said to Him, “Yes, Lord; You know that I love You.” He said to him, “Shepherd My sheep.” He said to him the third time, “Simon, son of John, do you love Me?” Peter was hurt because He said to him the third time, “Do you love Me?” And he said to Him, “Lord, You know all things; You know that I love You.” Jesus said to him, “Tend My sheep."
For each of Peter's denials Jesus gave Peter the opportunity to express his love for Jesus. Jesus also gave Peter something 'to do' as an expression of his love for Jesus. Jesus asked Peter to tend to - shepherd - His sheep.
Jesus' commands are not burdensome when we love Him. When we love someone we want to find ways to 'do' for them. Love demands to find expression in action. And, when we love, the action is not burdensome. You have probably heard it said, "Love is a verb."
This is not 'works' salvation. Truly it is the wonderful grace of Jesus that we inspired and able to die to ourself, being set free from the bondage of sin and death, that we may express our love and gratitude for Him in obedience to His commands. All commands are fulfilled in love, after all.

