Though Peter sometimes got into trouble with his words (Matthew 16:21-23; Mark 8:31-33), we do find that he had a lot of good things to say very confidently, especially when Jesus asked who His disciples thought he was in Matthew 6:15-17, Mark 8:29, and Luke 9:20. He also absolutely knew that Jesus was the Messiah. He proclaimed this without doubt in John 6:67-69. Peter even proclaimed that he would never leave Jesus, no matter what (Matthew 26:35; Mark 14:29; Luke 22:33; John 13:37).
Unfortunately when push came to shove, Peter fell short. Fearing the implications of being connected with Jesus at Jesus’ mock trial, Peter denied ever knowing Jesus, going so far as to swear an oath about it (Matthew 26:69-75; Mark 14:66-72; Luke 22:55-62; John 18:16-17, 25-27). Realizing what he had done, Peter very quickly left and wept very bitterly and loudly.
After Jesus rose from the dead and saw His disciples, we don’t see Him bring up this denial and outright reprimand Peter. Jesus did gently bring up the denial when asking Peter if he loved Him (John 21:15-17), but Jesus had already forgiven Peter. Jesus was giving Peter a chance to affirm his love for Him as many times as he had denied it, and then charged him with an important responsibility.
Later on in Acts 2 (specifically verses 14-40), we see Peter doing just what he was supposed to be doing, proclaiming his love for and belief in Jesus without backing down. He continued to live his life proclaiming all he knew about Jesus. Look further along in the book of Acts to see!
You can never go so far that Jesus will not forgive you if you ask. You can never go so far that Jesus can’t help you get it right the next time.