In the moments before Jesus went to the cross, Jesus made a lot of promises as well as calls for the disciples. One of the calls involves keeping Jesus's commandments. Jesus proclaimed that if the disciples love Jesus, they should keep Jesus's commandments (14:15). Loving someone means caring about someone, and Jesus wants the disciples to live empowered rather than in fear -- hence the various commandments Jesus made in John 13-14.
Speaking of living empowered, Jesus made yet another promise regarding a Helper. Jesus promised the disciples "another Helper" sent by the Father that would "abide with [them] forever" (14:16). Said helper is the Spirit, and it is commonly known as the Holy Spirit. The world does not know the Holy Spirit, but the disciples do (as the Holy Spirit has the same character as Jesus and Father), and the Holy Spirit would be with the disciples. In other words, the disciples do not have to do the commandments alone. They get the lifelong companionship of the Holy Spirit, which is directly sent by the Father.
Jesus also promises the disciples that he "will not leave [them] orphans" but would rather "come to [them]" (14:18). Although the disciples would face time without Jesus, said time is not permanent. In fact, while the world may not be able to see Jesus, the disciples will later be able to see Jesus, and they will live too (14:19). Plus, Jesus promised the disciples that they will know Jesus fully -- especially with how He is in the Father and the Father is in Him (14:20).
And remember Jesus's call to keep Jesus's commandments? That's not without a promise -- the disciples would be loved by the Father and Jesus himself (14:21)!