"Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous." Within a marriage, partners are meant to be faithful to God and each other. "The sexually immoral person sins against his own body." Hebrews 13:4 (ESV)
The blood of Christ was shed so that we might have a relationship with God. That relationship is only made possible because Jesus was...
1 Thessalonians 4:3 - For this is the will of God, your sanctification; that is, that you abstain from sexual immorality;
Therefore I tell you, whatever you ask in prayer, believe that you have received it, and it will be yours.1 John 5:14-15 (ESV)