Backsliding is the same thing as sinning. God will always forgive if we ask Him with a contrite (sincere) heart. If we intentionally "backslide," knowing that we are sinning, then no, God will not forgive.
Every sin is recorded unless you ask for forgiveness for that sin, "if you ask for forgiviness, God will throw the sin in the Dead Sea and never speak of it again." in other words you cannot be charged with a sin.