Lord Kṛṣṇa said, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66):
"You give up all your material engagements. Simply just surrender unto Me. I shall give you all protection from all reaction of your past sinful activities." Because we are creating our next body in this life. So if we become sinful, or if we act only sinful activities, then we get next body a very lower class of body, even as the germ in the stool. You see? There are so many varieties of bodies. And if we act nicely, piously, then we get better body. Ūrdhvaṁ gacchanti sattva-sthāḥ.
Those who are acting, those who are situated on the platform of goodness, they are promoting their existential status in higher planets. Ūrdhvaṁ gacchanti sattva-sthā madhye tiṣṭhanti rājasaḥ (BG 14.18):
And those who are in the modes of passion, they will remain here. And jaghanya-guṇa-vṛtti-sthā adho gacchanti tāmasāḥ: and those who are very addicted to all abominable habits, they are clearing their way to hellish life. So to abominable life is these four principles. That we are trying to avoid.